2824:
6990:
333:
12152:
5438:
7688:
3951:
10518:
9443:
9303:
3399:
16735:
13638:
16747:
1828:
9014:
8705:, which can be difficult to continuously track because of their size and great distance from Earth. Very short observation arcs, e.g. where the time between the initial observation and the most recent observation is less than 30 days, are of limited descriptive power because they represent only a very small fraction of the total path traced by the object in its
1492:
13617:, and is useful in specifically identifying small bodies observed before and after planetary encounters, as its numerical value remains largely constant throughout the body's lifetime. It is also used to distinguish between different kinds of orbits which are characteristic of different classes of bodies.
12446:
that has an anomalously high rate of star formation. The criteria for a starburst is a star formation rate that would normally consume the galaxy's available supply of unbound gas within a time period shorter than the age of the galaxy. Most starbursts occur as a result of galactic interactions, such
14003:
that is observed to vary in brightness. This variation may be periodic, with one or more cycles that last hours, days, months, or even years. Some stars vary in an irregular manner, while others undergo cataclysmic changes in brightness. Other forms of variability are intrinsic changes to the star's
13848:
The time period immediately before sunrise and after sunset during which, despite the Sun being completely below the horizon, the scattering of sunlight by the Earth's atmosphere supplies significant illumination to the ambient environment. Several definitions of twilight are commonly distinguished,
3195:
which appear near each other on the celestial sphere, either because the two stars coincidentally lie along nearly the same line of sight from the Earth, though they are in fact physically distant from each other, or because the two stars are actually located in physical proximity to each other, by
8228:
The human eye as used without any magnifying or light-collecting optical aid, such as a telescope, nor any eye protection. Many astronomical objects emit or reflect visible light that is sufficiently bright to fall within the limits of normal human visual perception, allowing observers to see them
13365:
A branch of astronomy that uses analytical and computational models based on principles from physics and chemistry to describe, explain, and model the properties of astronomical objects and phenomena, with the ultimate goal of accurately predicting the observable or testable consequences of those
11657:
between the Sun and the Earth. Because all three bodies are continuously moving, the shadow of the Moon traces out a narrow path across the Earth's surface, and from any given location within or very close to this path, the eclipse is visible only for a short duration. Depending on the observer's
3303:
that are cooler and less massive. The term originated from historical stellar models that assumed stars began their early life at a high temperature then gradually cooled off as they aged. It may be used to refer to the higher-temperature members of any particular population or category of stars,
325:) to 1 (indicating total reflection). The albedo reported for an astronomical body may vary widely by the spectral and angular distribution of the incident radiation, by the "layer" of the body being measured (e.g. upper atmosphere versus surface), and by local variation within these layers (e.g.
3705:
and change over time. The primary use of astronomical quantities specified by epochs is to calculate other relevant parameters of motion in order to predict future positions and velocities. In modern usage, astronomical quantities are often specified as a polynomial function of a particular time
10797:
A grid of fine lines or crosshatches engraved upon a transparent glass plate, which when placed in front of film during a photographic exposure produces a corresponding grid in the resulting photograph by creating permanent shadows on the film negative. These grids are used in some photographic
6340:, which is a plot of stars having the same mass but differing ages. In fact, multiple evolutionary tracks can be used to build isochrones by putting curves through equal-age points along the tracks. When the mass of a star can be determined, an isochrone can be used to estimate the star's age.
10836:
3605:
1326:
A gaseous envelope held in place by the gravity of a planet. This shell of gas has no clearly defined exterior boundary, but instead grows increasingly tenuous with altitude. The term can also be applied to a stellar atmosphere, referring to the visible outer layers of a
9652:
is not an accurate representation of the body's actual orbit. Perturbing forces may include the gravitational forces exerted by any number of additional bodies, the off-center gravitational forces which are consequences of bodies not being perfectly spherical, and/or
8397:
A type of elementary particle, electrically neutral and with an extremely small rest mass, that interacts with other particles only via the weak interaction and the gravitational interaction. Neutrinos therefore typically pass through normal matter unimpeded and
5539:
and other elements. Because O-type stars have relatively short lifetimes (typically a few million years), the presence of an H II region indicates that massive star formation has taken place recently at that location. H II regions are often found in the arms of
3894:
The minimum speed that must be achieved for a free, non-propelled object to escape from the gravitational influence of a massive body, i.e. to achieve an infinite distance from it; more generally, escape velocity is the speed at which the sum of an object's
3428:
23.4 degrees with respect to the ecliptic. To an observer on Earth, this means that the path the Sun appears to follow upon the celestial sphere is not a straight line (i.e. the ecliptic does not appear "flat"). Twice during each complete orbit, at the two
12078:
in the
Northern Hemisphere, is the annual date featuring the longest duration of daylight and the shortest duration of nighttime for any given point in the Northern Hemisphere; the reverse is true in the Southern Hemisphere, where the June date is the
6974:). There are also intermediate phases, during which the visible side may be only partially sunlit, e.g. when the Moon appears as a crescent. During the part of the lunar cycle in which the illuminated portion is growing larger, the Moon is said to be
10529:
when its position as viewed from Earth is at a right angle to the direction of the Sun. In such cases the moon or planet appears to be in its quarter phase (or nearly so), where half of the body is illuminated by the Sun and the other half is in
8938:
positioned at a focal point of each ellipse. The word "orbit" can variously refer to the elliptical trajectory itself or the act of following this trajectory, and can refer to a stable, regularly repeating trajectory as well as a non-repeating
6591:
at which a smaller object will maintain a constant position relative to the larger bodies. At other locations, a small object would eventually be pulled into its own orbit around one of the large bodies, but at the
Lagrangian points the
6604:
all align in a way that causes the small object to become "locked" in a stable or nearly stable relative position. For each combination of two orbital bodies, there are five such
Lagrangian points, typically identified with the labels
12534:, located above the stellar core, radiation zone, and convection zone. Although it constitutes only a small portion of the star's mass, for some evolved stars the stellar envelope can encompass a significant fraction of the radius.
8887:
The positioning of two celestial objects on opposite sides of the sky, from the perspective of an observer. This occurs, for example, when a planet makes its closest approach to the Earth, placing it in opposition to the
7112:, where the lower the value, the brighter the object. By convention, a first magnitude star is 100 times as bright as a sixth magnitude star. Magnitude 6 is considered the lower limit of objects that can be seen with the
6456:(or sometimes a straight line) in three-dimensional space. Kepler orbits are idealized mathematical constructions which consider only the point-like gravitational attraction of two bodies, neglecting more complex orbital
953:
A field that studies the geology of solidified bodies such as the planets and their moons, asteroids, comets, and meteorites. Investigations are centered around the composition, structure, processes, and history of these
11651:, in which a portion of the Earth passes through the shadow cast by the Moon, temporarily blocking sunlight, fully or partially, from reaching that portion of the Earth's surface. A solar eclipse occurs when the Moon is
10710:
point and extends toward the higher luminosity and lower temperature range until reaching the red-giant tip. This branch consists of older stars that have evolved away from the main sequence but have not yet initiated
6378:
seconds each. Because these are units of constant duration, the Julian year is also constant and does not vary with a specific calendar or with any of the other means of determining the length of a year, such as the
2476:
as a bright glow surrounding the lunar disk. The temperature of the corona is much higher than that of the stellar surface, and the mechanism that creates this heat remains subject to debate among astronomers.
11590:) on consecutive days. Because the Earth's orbit around the Sun affects the angle at which the Sun is seen from the Earth, the Sun appears to take slightly longer to return to the same position than do the
7668:
and is estimated to contain 100–400 billion stars and at least that number of planets. The Solar System is located on the inner edge of one of the Milky Way's spiral arms, about 27,000 light-years from the
12155:
The Earth's atmosphere permits certain wavelengths of electromagnetic energy to pass through but reflects or absorbs others, making it difficult or impossible to detect them from the surface. As a result,
9315:
between the orbital periods of two planets (small bodies), both of which are orbiting a large central star. The inner planet completes two revolutions in the time it takes the outer planet to complete one.
6363:
of gas will begin to undergo collapse and form stars. A cloud can become unstable against collapse when it cools sufficiently or has perturbations of density, allowing gravity to overcome the gas pressure.
15436:
Rodono, M.; et al. (September 1986), "Rotational modulation and flares on RS CVn and BY Dra-type stars. I - Photometry and SPOT models for BY Dra, AU Mic, AR Lac, II Peg and V 711 Tau (= HR 1099)",
8563:
The quantity of some specified particle or object class per unit volume. For atoms, molecules, or subatomic particles, the volume is typically in cm or m. With stars, cubic parsecs (pc) are often used.
3792:, and a right-handed convention. This system is widely used to specify the positions of celestial objects as viewed from Earth. It may be implemented in either spherical or rectangular coordinates.
1200:, and their appearance in scientific literature has become increasingly infrequent. Exceptions include the symbols for the Sun (☉), the Earth (🜨), and the Moon (☾), which are sometimes used for
8133:. Because these four extrasolar messengers are created by different astrophysical processes, their presence or absence during a celestial event can reveal useful information about their sources.
9673:
or angle between an orbiting body and the Sun as viewed from a particular perspective, such as the Earth. It determines the amount of a planet or moon's visible surface that lies in shadow.
9342:, or its speed relative to the center of mass of the most massive body in the system. The term may be used to refer to either the mean orbital speed, i.e. the average speed over the entire
5878:
at a ground observer's particular location, the concept of the hour circle is employed to describe the longitudinal position of a celestial object relative to the observer's local meridian.
1562:, the barycenter may actually be located within the radius of the star, such that the planet appears to orbit the star itself, though both bodies actually orbit the shared barycenter.
5222:
or to the position of an observer, i.e. as defined by a straight line between the center of the Earth (or the observer) and the object at a given time, without any corrections for
5639:
and a vast region of space beyond it. Its outer limit is often considered the boundary between matter originating from the Sun and matter originating from the rest of the galaxy.
16784:
5768:
The apparent boundary between the surface of a celestial body and its sky when viewed from the perspective of an observer on or near that body's surface; more specifically, the
12330:
within its core. Astronomers can determine the mass, age, platemperature, chemical composition, and many other properties of a star by observing its motion through space, its
9523:
For a variable star, this is the highest amplitude achieved during a rise in luminosity, followed by a decline. This data point can provide useful distance information for a
184:
star having spectra dominated by Balmer absorption lines of hydrogen. Stars of spectral class A are typically blue-white or white in color, measure between 1.4 and 2.1 times
5202:) disk with the same cross-section. It is a measure of how much of the incoming illumination is being scattered back toward an observer and has a value between zero and one.
10948:
matches an orbiting body's gravitational self-attraction. Inside this limit, the tidal forces will cause the orbiting body to disintegrate, usually to disperse and form a
6851:. The angle is typically measured eastwards from the reference direction to the ascending node (i.e. counterclockwise as seen from the north). It is one of six canonical
2317:
or share a common origin, or they are known to be gravitationally bound (in which case their proper motions may be rather different but average to be the same over time).
884:
An interdisciplinary field that studies the origins, evolution, distribution, and future of living systems in the universe, encompassing research on organic compounds in
10367:
and has since undergone internal melting to produce an interior of non-uniform composition. Protoplanets represent an intermediate step in the formation of a full-sized
7290:, the mean anomaly does not correspond to a real geometric angle but is instead a contrived parameter used to make calculating the position of the orbiting body in the
7455:
by collisions with air molecules in the upper atmosphere, leaving an ionization trail as a result of its rapid motion and sometimes also shedding material in its wake.
6948:
that is illuminated by direct sunlight as viewed from Earth. This shape is referred to as a phase because it gradually changes in a regular cycle over the course of a
14096:. Since most absorption lines are caused by elements other than hydrogen and helium—what astronomers refer to as "metals"—these are sometimes called metal weak stars.
13391:
galaxy where the spiral arms are found and where most of the star formation takes place. It is about 300–400 parsecs (980–1,300 light-years) deep and centered on the
11407:
on consecutive nights. The Earth's sidereal day is equal to approximately 86,164.09 seconds (23 hours, 56 minutes, 4.09 seconds), about four minutes shorter than the
10258:
The main physical body of a gravitationally bound, multi-object system. The primary constitutes most of the system's mass and is generally located near the system's
3093:
and the other known planets, such that it appears to be "detached" from the rest of the Solar System. Detached objects are thus distinct from other populations of
3175:
over the course of one day. Diurnal motion is caused by Earth's rotation about its own axis, such that every object appears to follow a circular path called the
2432:
surrounding a specific and identifiable grouping of stars. The names of constellations are assigned by tradition and often have an associated folklore based in
10398:
A concentration of mass formed out of the contraction of a collapsing interstellar cloud. Once sufficient mass has fallen onto this central core, it becomes a
15364:
Bychkov, V. D.; et al. (April 2009), "Catalogue of averaged stellar effective magnetic fields - II. Re-discussion of chemically peculiar A and B stars",
6193:. This effect causes more distant objects such as stars to appear redder and dimmer than expected. It is not to be confused with the separate phenomenon of
2416:
as observed from a third body (usually the Earth), such that, from the observer's perspective, the objects appear to closely approach each other in the sky.
1080:
A list of astronomical objects, typically grouped together because they share a common type, morphology, origin, means of detection, or method of discovery.
16942:
16937:
13711:
as they pass in front of their host stars. A transit by an object that appears roughly the same size or larger than the body it is transiting is called an
1646:
A concentration of mass so compact that it creates a region of space from which not even light can escape. The outer boundary of this region is called the
9920:
The process of separating out different constituents of a planetary body, causing it to develop compositionally distinct layers (such as a metallic core).
4391:
which are so distant from observers on Earth that they do not appear to move relative to each other, as opposed to the "foreground" of objects within the
16777:
14394:
8693:, which defines the length of the path traced by the object between these same observations. The term is primarily used in the discovery and tracking of
8638:
which are not gravitationally bound to each other, but move together through space in a loose association. The OB in the name is a reference to stars of
8229:
from the Earth's surface without any special equipment. Vision corrected to normal acuity using eyeglasses or contact lenses is still considered unaided.
7684:
2. The hazy band of light itself, which from Earth appears as a band because the galaxy's disk-shaped structure is viewed side-on from within.
319:
away from the body. It is a dimensionless quantity typically measured on a scale from 0 (indicating total absorption of all incident radiation, as by a
16899:
12020:
and flowing outwards at up to 900 kilometres per second (2,000,000 mph) into interplanetary space. Phenomena influenced by the solar wind include
11401:), measured as the time it takes for the fixed stars, as viewed from a particular point on the object's surface, to return to the same position in the
2230:. Because the energy output of a star varies by frequency as a function of temperature, the color index can be used to indicate the star's temperature.
2342:
with a very high mass relative to its radius, compared to most ordinary atomic matter. The term typically refers to very high-density objects such as
1863:; this means that the path of the Sun, as viewed from Earth, appears to move both above and below the celestial equator during the course of the year.
16665:
13155:
as observed from Earth, but can in principle be calculated with respect to the sky as observed from any body. It is related to but distinct from the
13685:
2. An astronomical event during which a celestial body or object passes visibly across the face of a much larger body. An example is the
11206:(or any other distant luminous object) as viewed through a medium, such as the Earth's atmosphere, caused by the passing of light through layers of
13283:
on the spectra of other stars. For example, water vapor in the atmosphere creates significant telluric absorption bands at wavelengths above 6800
11130:
A broken arc of illuminations seen at the limb of very young or very old lunar crescents. The visual similarity to the moments before and after a
16672:
11962:, as viewed from a given location on the Earth's surface. Because the duration of this interval changes during the Earth's orbit around the Sun,
8857:
A measure of the resistance of a medium to the radiative transmission of energy. Within a star, it is an important factor in determining whether
7545:
within an astronomical object. Note that this definition includes elements that are not traditionally considered metallic by chemical convention.
5890:
that display pulsation frequencies of two different classes of variables. An example are variables displaying characteristic frequencies of both
1780:. The focus remains stationary as the telescope is re-oriented, which is advantageous for the stable mounting of heavy spectroscopic instruments.
1598:. It depicts a starting condition of extremely high density and temperature, followed by an ongoing expansion that led to the current conditions.
10345:
The rate of angular motion of an object over an interval of time, usually years. For stars, this is typically given in milliarcseconds per year.
16770:
10444:
that emits a beam of electromagnetic radiation. This beam is observed only when it is pointing toward Earth, making the object appear to pulse.
10798:
telescopes to produce reference markers in photographs of distant stars, allowing precise and convenient measurement of astrometric positions.
7001:
are caused by the visible side of the Moon being alternately illuminated by sunlight and immersed in shadow during its orbit around the Earth.
16929:
15069:
Rufener, F.; Bartholdi, P. (June 1982), "List of 333 variable, microvariable or suspected variable stars detected in the Geneva photometry",
11578:, measured as the time it takes for the Sun, as viewed from a particular point on the Earth's surface, to return to the same position in the
10614:. Positive values are used to indicate a receding object. An object such as a star can undergo changes in its radial velocity because of the
14336:
A band of light in the night sky, thought to be sunlight reflected from cometary dust concentrated in the plane of the zodiac, or ecliptic.
11435:, e.g. the Earth's orbital period around the Sun. The name "sidereal" implies that the object returns to the same position relative to the
493:
A measure of the brightness of a celestial body as seen by an observer on Earth, adjusted to the value it would have in the absence of the
15590:
13780:
of the ellipse. The true anomaly is one of three angular parameters that define a position along an orbital path, the other two being the
7896:, only one side of the Moon is ever visible from the Earth. Sunlight reflected from its surface makes the Moon appear very bright in the
15009:
The large scale structure of the universe; Proceedings of the
Symposium, Tallinn, Estonian SSR, September 12-16, 1977. (A79-13511 03-90)
9264:, etc., or any combination thereof) exist in some definite mathematical relationship with each other. Most commonly, the term refers to
16006:
11316:
system or star–planet system. When the distance between the orbiting bodies is unknown, the semi-major axis may be given as an angle.
8161:
that had the visual appearance of a galaxy with a particularly bright, star-like nucleus. As a group, they are intermediate between
252:. The material is acquired from a source external to the central object, and friction causes it to spiral inward towards the object.
5703:
allows its age to be estimated. Stars of similar types are also found grouped together in specific regions of the chart, including
14799:
14662:
Silaj, J.; Jones, C. E.; Tycner, C.; Sigut, T. A. A.; Smith, A. D. (March 2010), "A Systematic Study of Hα Profiles of Be Stars",
8926:
around a planet. Though the smaller body is often said to orbit the larger body itself, both bodies actually follow approximately
8788:
is hidden by another, nearer body or object that passes between it and the observer, thereby blocking the first object from view.
1135:. Though the terms astronomical "object" and astronomical "body" are often used interchangeably, there are technical distinctions.
16384:
14952:
Forbes, John C.; Loeb, Abraham (February 2019), "On the
Existence of Brown Dwarfs More Massive than the Hydrogen Burning Limit",
13397:. Stars belonging to this population generally follow orbits that lie close to this plane. This is in contrast to members of the
3759:
3465:
17:
11602:. The length of the solar day is also not constant, but rather changes over the course of the year because the Earth's orbit is
8614:
values over time, showing how observed data differ from theoretical values which have been calculated according to a particular
17034:
14513:
8199:. Thus, where the zenith is directly above an observer, the nadir is underfoot. The zenith and nadir form the two poles of the
7561:
that has survived its passage through the atmosphere to reach the surface of a planet or moon, usually ranging in size from 50
5840:, the hour angle is one of many ways commonly used to specify the longitudinal position of an object upon the celestial sphere.
3974:
1231:
around the Sun, the astronomical unit is now more rigidly defined as exactly 149,597,870.7 kilometres (92,956,000 miles; 4.8481
661:(in geocentric and heliocentric orbits) or at which the orbiting object moves away from the observer (in orbits outside of the
2561:
or has fallen on Earth, generally composed of fine particles of solid matter far smaller than those found in terrestrial dust.
16957:
16952:
15514:
14404:
6187:
An effect produced by the incremental absorption and scattering of electromagnetic energy from interstellar matter, known as
3028:(in geocentric and heliocentric orbits) or at which the orbiting object moves toward the observer (in orbits outside of the
14426:
8841:
and a spherical outer Oort cloud. The outer limit of the Oort cloud is often considered the cosmographical boundary of the
2866:
are measured in positive degrees from 0° to 90°, while coordinates to the south are measured in negative degrees. See also
13143:. Synodic period is most commonly used to indicate the elapsed time between a given body's consecutive appearances in the
3542:
shape and a smooth, nearly featureless appearance. They are one of three main morphological classes of galaxy, along with
16874:
16829:
12164:
instruments are often placed in orbit, above the atmosphere, where detection of all parts of the spectrum is uninhibited.
9348:, or the instantaneous speed at a particular point in the orbit. Maximum instantaneous orbital speed typically occurs at
7623:. Detecting microvariability typically requires a sufficient number of observations to rule out random error as a source.
14477:
Noyes, R. W.; et al. (April 15, 1984), "Rotation, convection, and magnetic activity in lower main-sequence stars",
13513:
and gases which are stripped from gas clouds and star clusters because of interaction with the gravitational field of a
7471:
that originated in outer space and survived its passage through the atmosphere to reach the surface of a planet or moon.
6707:
A unit of length used to express astronomical distances that is equivalent to the distance that an object moving at the
2610:. Collisions of cosmic rays with the Earth's atmosphere can produce dramatic effects both in the air and on the surface.
1381:. The phenomenon is similar to but much larger in magnitude than other changes in the alignment of Earth's axis such as
17059:
16999:
16972:
15660:
15633:
15575:
15475:
15420:
15321:
15107:
14777:
14647:
14567:
14434:
9987:, with the aim of understanding their formation, composition, topography, dynamics, and interactions with other bodies.
15174:
Miller, J. S. (December 1981), "The galaxy components of BL Lacertae objects, N systems, and quasi-stellar objects.",
11840:
equals 2/3), or approximately 695,700 kilometres (432,300 mi). It is commonly used to express the radii of other
10106:
whose internal strength is dominated by self-gravity and whose orbital dynamics are not significantly affected by gas
10100:
Any solid object (generally larger than 1 kilometre (0.62 mi) in diameter) that arises during the formation of a
5284:
such that, to an observer on Earth's surface, the orbiting object appears motionless, in a fixed position in the sky.
16924:
16884:
16809:
15744:
15294:
15046:
14852:
14740:
14461:
12599:
2004:
9628:
The complex motion of an astronomical body that is subject to forces other than the gravitational attraction of its
1960:, i.e. the two points in the sky that are directly overhead the terrestrial North and South Poles, around which all
17095:
16994:
16912:
16907:
16503:
14361:
12205:
as they would appear from a particular date, time, and location on Earth. It relies on the mathematical methods of
11239:
9782:
An imaginary plane that is perpendicular to the line of sight. Typically this is used as a reference plane for the
7662:
that cannot be individually distinguished by the naked eye. The Milky Way Galaxy has a diameter of 100,000–200,000
6136:
14907:
Sánchez Arias, J. P.; et al. (January 2017), "Asteroseismology of hybrid δ Scuti-γ Doradus pulsating stars",
8428:, but with a radius of only 12 km (7.5 mi), making them among the densest known objects in the universe.
7034:. A MACHO is a body that emits little or no radiation and drifts through interstellar space unassociated with any
5752:. It is computed with respect to the next most gravitationally attractive object, such as the nearest star or the
2168:. Schröder et al. (2009) divide solar-type stars into four groups depending on their activity index: very active (
1469:
An angular measurement of an object's orientation along the horizon of the observer, relative to the direction of
16321:
14711:
14351:
13131:
The time it takes for a body visible from another body (often the Earth) to complete a cycle with respect to the
12980:, including that produced by the effects of rotation. It is typically expressed in units of acceleration such as
11351:
of the Earth begins to tilt away from the Sun, and typically occurs on or near
September 22 each year. It is the
11220:, since light rays near the horizon must travel longer paths through the atmosphere before reaching the observer.
8422:
with no electrical charge. Typically, neutron stars have a mass between about 1.35 and 2.0 times the mass of the
6820:
5643:
4858:. Galaxies may contain hundreds of billions of stars and are categorized according to their visual morphology as
4198:. These field stars are important to identify in order to prevent them from contaminating the results of a study.
3903:
is equal to zero. It is a function of the mass of the body and of the distance between the object and the body's
13961:
Universe, whose spatial extent is unknown because it is not directly measurable; this is distinguished from the
10610:
The velocity of an object along the line of sight to the observer, which in astronomy is usually determined via
5319:, such that the orbiting object appears to return to exactly the same position in the sky after a period of one
1365:
over a cycle of approximately 25,772 years, which is caused predominantly by the gravitational influence of the
362:
A large area on the surface of a reflecting object that shows a significant contrast in brightness or darkness (
17085:
15999:
15877:
15548:
15268:
6408:
3900:
15219:
The Light-Time Effect in
Astrophysics, Proceedings of ASP Conference Series, held in Brussels 19-22 July 2004.
11276:
The angle at the position of an observer subtended by the equatorial radius of the Sun, the Moon, or a planet.
3435:, the Sun's path appears to intersect the celestial equator, though the two planes are never in fact coplanar.
1192:. Many of these symbols were commonly used historically, though in the modern era they are usually limited to
17054:
17044:
16869:
16864:
16607:
14120:
process with its constituent atoms, so the object's energy output normally comes from radiative cooling. See
11108:
10128:
which are left over from the formation process. There is no precise distinction between a planetesimal and a
9293:
in the same time it takes
Neptune to complete three. Resonance may act on any time scale, from short-term to
8107:
through the coordinated observation and interpretation of four disparate classes of "messenger" signals with
6886:
6375:
2278:
2820:
being emitted from the star system, as the orbiting debris re-radiates the star's energy into space as heat.
1422:
The angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its
16919:
16879:
16273:
15036:
12066:
is either 90 degrees or 270 degrees. The solstices occur on or near June 20 and
December 21 each year. The
10331:. The actual separation of the two objects depends on the angle of the line between the two objects to the
10173:
5457:
3746:
2262:
15813:
Yuan, Feng; Narayan, Ramesh (September 2004), "On the Nature of X-Ray-Bright, Optically Normal
Galaxies",
7215:
of the Earth begins to tilt toward the Sun, and typically occurs on or near March 20 each year. It is the
3359:. Hence, the position of the Sun as viewed from the Earth defines the intersection of this plane with the
2598:
and atomic nuclei which move through space at nearly the speed of light, and which may originate from the
16967:
16962:
16859:
16844:
13165:) and the body from which it is being observed (e.g. Earth) are independently orbiting a third body (the
12605:
1. The region within the volume of a star that transports energy from the stellar core to the
11030:
10815:
10290:
10226:
7711:
7013:
4591:
2565:
1478:
11658:
location and on the apparent sizes of the solar and lunar disks in the sky, an eclipse may appear to be
10620:
of another body, or because of radial pulsations of its surface. The latter, for example, occurs with a
8585:
which results from the combined effects of small, short-term variations. Nutation is distinguished from
7591:, usually weighing less than one gram. If it survives to reach a planetary surface, it is then termed a
1966:
appear to revolve during the course of a day. The celestial poles form the north and south poles of the
17019:
16989:
16750:
16658:
16440:
16232:
15736:
14356:
14200:
14113:
12965:
12263:
6741:-scale distances in non-specialist publications, the unit of length most commonly used in professional
5535:
from these hot stars ionize gas in the surrounding environment, and the nebular gas shines brightly in
4606:
3440:
2823:
2641:
2207:
15760:
Pace, G.; et al. (April 2003), "The Wilson-Bappu effect: A tool to determine stellar distances",
15491:
13097:. As it does on Earth, an object's synodic day may change slightly in duration over the course of the
5290:
are often placed in geostationary orbit so that antennas on Earth do not have to rotate to track them.
3452:
commonly used to specify the apparent positions, orbits, and axial orientations of objects within the
3089:
is so distant that the object is only moderately or weakly affected by the gravitational influence of
1310:(rather than the positions or motions of objects in space, which is more specifically the emphasis of
16679:
16496:
16461:
16454:
16301:
15992:
15543:, Space Telescope Science Institute Symposium, vol. 12, Cambridge University Press, p. 97,
13802:
12981:
12143:
11623:(averaged over the Earth's orbital period) is currently equal to 86,400 seconds, or exactly 24 hours.
11179:
10662:
10332:
9914:
9240:
bodies exert regular, periodic gravitational influences on each other such that one or more of their
8114:
8089:
4882:
are between 1,000 and 3,000 parsecs (3,300 and 9,800 ly) in diameter though some, including the
3982:
3876:
the equator, and the durations of day and night are approximately equal all over the planet. Compare
3519:
15676:
Heller, R.; et al. (April 2011), "Tidal obliquity evolution of potentially habitable planets",
13695:, which was visible from Earth in 2004 and 2012. Because a transit results in a decrease in the net
9299:, and often leads to either long-term stabilization of the orbits or their eventual destabilization.
7918:
is often used specifically to describe the orbit, gravity, and other properties of the Earth's Moon.
7850:
A dimensionless quantity that characterizes the radial distribution of mass inside a planet or moon.
3681:
A moment in time used as a reference point for some time-varying astronomical quantity, such as the
803:; and bodies similar to asteroids in size and composition but which lie beyond Jupiter are known as
547:. The term may also be used to refer to the value of the distance rather than the point itself. All
16854:
16824:
16702:
16468:
15123:
13549:
10847:
orbit, a satellite (red) orbits in the direction opposite the rotation of its primary (blue/black).
10574:
9622:
9422:, characterized generally by extremely low densities of particles, extremely low temperatures, and
7835:
5536:
5268:, which maintains a constant altitude of 35,786 kilometres (22,236 mi) directly above Earth's
4442:
2227:
388:. The spectrum of the Am stars shows abnormal enhancements and deficiencies of certain metals. See
379:
276:
15652:
Dynamics of the Milky Way: Tidal Streams and Extended Distribution Functions for the Galactic Disc
15149:
14559:
Astronomical Applications of Astrometry: Ten Years of Exploitation of the Hipparcos Satellite Data
9432:
is intergalactic space, and even galaxies and star systems consist almost entirely of empty space.
6989:
5430:, which can bend passing light from a distant source by a noticeable degree. The effect, known as
17009:
16984:
16819:
16814:
16563:
16349:
16208:
16187:
16146:
16110:
16078:
15538:
14269:
14134:
13727:
13428:
The transfer of momentum between an astronomical body and an orbiting satellite as the result of
12882:
12722:
12089:
11544:
11153:
10808:
Orbital or rotational motion of an object in the direction opposite the rotation of the object's
10471:
10214:
refers to a steady change in the orientation of an orbit, such as the precession in the orbit of
9877:
9810:
9661:
9598:
8736:
7884:, completing a full orbit every 27.3 days. The Moon's gravitational influence is responsible for
7650:. The name describes the galaxy's appearance from the Earth: a hazy band of light visible in the
7145:
6367:
5955:
4234:
lower (i.e. brighter) than 1.50. There are 22 stars that are classified as first magnitude stars.
4202:
4118:
4003:
2783:, at which it reaches its lowest point, nearly 12 hours later. When not otherwise qualified, the
2388:
1576:
were generated in the early Universe, including the means by which baryons outnumber antibaryons.
773:. Asteroids are somewhat arbitrarily distinguished from many different types of similar objects:
400:
256:
15097:
10283:
Orbital or rotational motion of an object in the same direction as the rotation of the object's
10122:
during the process of planet formation, but is also sometimes used to refer to various types of
8468:, and more specifically when clear weather and low levels of ambient light permit visibility of
1099:
A type of naturally occurring physical entity, association, or structure that exists within the
17039:
17024:
16616:
16489:
16482:
16405:
16199:
15598:
14249:
14156:. This linear relation makes it useful for determining the distances of G, K, and M-type stars.
14025:
13887:
13809:
13654:
13276:
12668:
12567:
12538:
11299:. It is expressed in units of length and often used to give a physical dimension to a two-body
11211:
11157:
10478:
10460:
10399:
10192:
8003:
6181:
5895:
5600:
5409:
5405:
in having a much higher combined mass, with a typical lifespan extending for billions of years.
5199:
4543:
4278:
3967:
3621:
2836:
2528:
2297:
A term used to indicate that two or more stars share the same motion through space, within the
2247:
2117:
2074:
1694:. At rotational velocities beyond this point, the star begins to eject matter from its surface.
1065:
899:
15730:
15619:
15465:
14763:
14726:
14451:
11886:
and all of the objects that orbit it, either directly or indirectly, including the eight true
4158:. An increase in faculae as a result of a stellar cycle increases the star's total irradiance.
2178:
above −4.2), active (−4.2 to −4.75), inactive (−4.75 to −5.1), and very inactive (below −5.1).
2064:, and generally also have unstable orbits because they cross the orbits of one or more of the
50:. The field of astronomy features an extensive vocabulary and a significant amount of jargon.
16894:
16586:
16280:
16218:
16041:
15867:
15565:
15410:
15284:
14557:
14514:"Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo"
14420:
14366:
13359:
13280:
12486:
11511:
10955:
10707:
10071:
9683:
generally have low phase angles as seen from Earth, so they often appear as a slim crescent;
9510:
9390:
8567:
8432:
7342:
The measurement of positions of celestial objects based on observation of the times of their
7096:
6635:
4585:. It is approximately 8,200 parsecs (27,000 ly) away from Earth in the direction of the
4339:
3508:
3410:(grey) is defined by the Earth's orbit around the Sun, and is distinct from the plane of the
2489:
2314:
994:
The branch of astronomy that involves precise measurements of the positions and movements of
909:
557:
494:
15783:
15699:
15650:
15450:
15350:
15311:
15082:
14930:
14880:
Chebotarev, G. A. (April 1964), "Gravitational Spheres of the Major Planets, Moon and Sun",
14532:
14140:
A correlation between the width of the singly ionized calcium K-line (Ca II K) at 3933
13832:
width. It can be used to estimate the distance of the galaxy, and hence forms a rung on the
13446:
orbit will gradually recede from its primary while slowing the rotation rate of both bodies.
11019:
in which they formed, or otherwise have never been gravitationally bound to any star system.
10315:
The observed physical separation between two astronomical objects, as determined from their
5834:, and the plane containing Earth's rotational axis and the object of interest. Analogous to
1111:, consisting perhaps of multiple bodies or even other objects with substructures, such as a
17064:
17049:
17014:
17004:
16849:
16578:
16510:
16328:
16266:
16057:
16034:
16027:
15931:
15832:
15779:
15695:
15625:
15446:
15373:
15346:
15222:
15183:
15078:
15012:
14971:
14926:
14889:
14671:
14602:
14528:
14486:
14346:
13664:
13593:
in which the three bodies all differ greatly in mass. The parameter is calculated from the
13287:. These features need to be corrected for in order to more accurately measure the spectrum.
12319:
12107:
11112:
10621:
10611:
10411:
9818:
9524:
8976:
8881:
8871:
A gravitationally bound group of up to one thousand stars that formed together in the same
8546:
8073:
which travel together through space. Although the members were formed together in the same
7316:
6687:
5891:
5294:
4649:, usually home to a very dense concentration of stars and gas. It almost always includes a
4309:
4238:
4224:
3308:
2370:
1857:. Note that the Earth's rotational axis is not perpendicular to the ecliptic but rather is
1777:
1474:
1307:
717:
604:
15897:
13321:
slows to subsonic speeds (relative to the Sun) as a result of interactions with the local
6986:. The phase of the Moon at any particular time appears the same from every point on Earth.
6096:, both appear to travel with the Sun across the sky. This is in contrast to the so-called
2438:
332:
8:
17029:
16979:
16889:
16839:
16709:
16651:
16447:
16398:
16294:
16241:
16064:
15872:, Astronomy and Astrophysics Library, Springer Science & Business Media, p. 39,
14732:
14018:
13629:
12741:
12581:
12178:
11697:
11214:
caused by small-scale fluctuations in air density, and are much more pronounced near the
10383:
10235:
9752:
9042:
8766:, which is concerned with calculating the measurable implications of astronomical models.
8727:
6146:
6045:
5281:
5238:
5118:
5015:
4749:
4513:
4137:
3907:. An object which has achieved escape velocity is neither on the surface nor in a closed
2222:
A numeric value that is used to compare the brightness of a star measured from different
1868:
1633:
1356:
1139:
1084:
669:
336:
47:
43:
16762:
15836:
15377:
15226:
15187:
15016:
14975:
14893:
14675:
14606:
14583:
Townsend, R. H. D.; et al. (May 2004), "Be-star rotation: how close to critical?",
14490:
13275:
with nearly featureless continuum spectra that can be used to correct for the effect of
11481:, i.e. the time interval between two successive returns of the fixed stars to the local
6177:, but is enhanced by traces of other elements contributed by matter expelled from stars.
5437:
3754:
3608:
A relatively small body (such as a planet) orbiting a larger one (such as a star) in an
3448:
667:). The position of the ascending node with respect to a reference direction, called the
17090:
16738:
16637:
16342:
16312:
16259:
16194:
16142:
16117:
15848:
15822:
15795:
15769:
15711:
15685:
15391:
15199:
14989:
14961:
14916:
14689:
14620:
14592:
14323:
14048:
13957:
that describe them. When not otherwise qualified, "the Universe" usually refers to the
13589:
13413:
13331:
13209:
12513:
12400:
system. In the broadest sense, very large groups of stars bound by gravitation such as
12206:
11243:
11238:
Any change in movement that happens over a very long time period. Examples include the
10316:
10219:
9719:
9701:
8969:
8618:. It is often used as a diagnostic tool to determine the accuracy of the model. With a
8502:
8419:
8118:
7828:
7687:
6334:
positions of stars having the same age but differing masses. This is in contrast to an
6110:
5474:
5418:
5195:
4797:
4486:
4231:
3917:
3671:
at various dates and times. Modern ephemerides are often provided by computer software.
3628:
2182:
1918:
958:
478:
316:
194:
14684:
12895:
which possess masses ranging from hundreds of thousands to many billions of times the
12151:
10860:
3504:
to the ecliptic. It may be implemented in either spherical or rectangular coordinates.
3101:
2852:
1968:
1808:
1636:, a type of optical illusion which is entirely distinct from true binary star systems.
42:, their sub-disciplines, and related fields. Astronomy is concerned with the study of
16644:
16630:
16429:
16414:
16391:
16335:
16103:
15873:
15740:
15715:
15656:
15629:
15571:
15544:
15471:
15416:
15395:
15386:
15317:
15290:
15264:
15260:
15203:
15103:
15042:
14993:
14773:
14736:
14693:
14643:
14615:
14563:
14457:
14430:
14400:
14258:
14245:
that is directly overhead from the perspective of a particular location on the Earth.
14127:
13954:
13291:
13246:(i.e. in the tangent plane). This component can be computed from the body's observed
13002:
12770:
12630:
12271:
11596:, which results in the solar day being on average about four minutes longer than the
11320:
10802:
10696:
10415:
10206:
9954:
9228:
9070:
8282:
8233:
7854:
7777:
7140:
6683:
6597:
6351:
6324:
6316:
5905:
5900:
5887:
5758:. Satellites moving outside this radius tend to be perturbed away from the main body.
4438:
4329:
4268:
4174:
that does not belong to a larger cluster of galaxies and is gravitationally isolated.
4064:
4030:
3925:
3733:
3683:
3675:
3526:
3379:
2970:
2679:
2675:
1784:
1738:
1691:
1687:
1540:
of each body participating in the system; its location is strongly influenced by the
1393:
1210:
1010:
865:
to distinguish it from other asteroid populations in other parts of the Solar System.
507:
The closest approach of one celestial object to another, as viewed from a third body.
15852:
15799:
14624:
13349:
from its dark side. The line moves as the object rotates with respect to its parent
13215:
The straight-line configuration of three celestial bodies in a gravitational system.
12062:
10502:
as viewed from the Earth. The term is used especially to describe the position of a
10486:
9823:
7617:, in which the amplitude of the fluctuations amounts to just a few thousandths of a
7132:
which form a continuous and distinctive band on plots of stellar temperature versus
5578:
4812:. Galactocentric distance may also refer to a galaxy's distance from another galaxy.
4283:
3935:
of a particular mass and composition is expected to follow during the course of its
3842:
2412:
2240:
A relatively small, icy body that displays extended features when it approaches the
1818:, this plane is currently inclined at an angle of 23.44 degrees with respect to the
1726:
1025:
A type of naturally occurring physical entity, association, or structure within the
16549:
16528:
16363:
16356:
15840:
15787:
15703:
15381:
15191:
14979:
14934:
14679:
14610:
14536:
14494:
13871:
13825:
13777:
13686:
13472:
12704:
12679:
12590:
12434:
12305:
12267:
12228:
11776:
11140:
11023:
10782:
10688:
10464:
10215:
9991:
9924:
9735:
9365:
9203:
9181:
8998:
8851:
8615:
8170:
6556:
6257:
6235:
6203:
6070:
5971:
5819:
5769:
5561:
5434:, can make background objects appear to an observer to take on a ring or arc shape.
5369:
5182:
5125:
4624:
3723:
3558:
3350:
3346:
2497:
2461:
2146:
1976:
1531:
1454:
1378:
1331:
1265:
1228:
52:
15967:
15915:
15707:
14938:
14541:
11980:
were employed by astronomers as time reckoning systems before the introduction of
8754:
and other astronomical instruments. It is concerned with recording data about the
6385:. It is therefore widely used as the basis for defining the standard astronomical
5818:
that passes through the celestial object; or, equivalently, the angle between the
16695:
16370:
16287:
16225:
16180:
16124:
15791:
15217:
Sterken, C. (July 2005), Sterken, C. (ed.), "The O-C Diagram: Basic Procedures",
15052:
14193:
14188:
14028:
of velocities about the mean velocity for a group of objects, such as stars in a
12957:
12841:
12713:
12195:
11900:
11417:
11280:
11057:
10921:
10852:
10655:
10647:
10628:
10604:
10569:
10551:
10268:
10124:
9931:
8858:
8683:
8666:
8494:
8291:
8274:
7815:
7719:
7389:
7166:
6489:
6063:
5465:
5129:
5041:
5008:
5004:
4992:
4663:
4661:
in a compact region than its surroundings. This excess luminosity is known as an
4651:
4615:
4575:
4550:
4505:
4450:
3950:
3888:
3870:
each year. On the day of an equinox, the center of the visible Sun appears to be
3593:
3494:
3291:
3115:
3046:
3001:
2963:
2931:
2904:
2817:
2298:
2275:
2251:
2089:
2012:
1754:
1355:. The term often refers in particular to the gradual shift in the orientation of
841:
775:
300:
27:
List of definitions of terms and concepts commonly used in the study of astronomy
15415:, Cambridge Astrophysics, vol. 34, Cambridge University Press, p. 25,
15221:, vol. 335, San Francisco: Astronomical Society of the Pacific, p. 3,
14092:
13834:
13440:
for both bodies as well as modification of their mutual orbit. A satellite in a
12098:
11956:, i.e. the time interval between two successive returns of the Sun to the local
10791:
8640:
8492:. The night sky remains a fundamental setting for both amateur and professional
6771:
6692:
5136:
5070:
explosions of high-mass stars. Short GRBs may also result from the collision of
4774:
4558:
3816:
Either of the two precise times of year when the imaginary plane of the Earth's
3095:
2993:
1223:
or secondarily between the Earth and distant stars. Originally conceived as the
1202:
16542:
16475:
16377:
15099:
Astronomy for beginners : all you need to know to get started in astronomy
14984:
14330:
14273:
14117:
14041:
14040:. This value can be used to derive the combined mass of the group by using the
13950:
13851:
13702:
13399:
13125:
12815:
12792:
12675:
12346:
12169:
12130:
12005:
11666:
11232:
11170:
10991:
10107:
9900:
9855:
9697:
usually have high phase angles, so that little of the shadowed side is visible.
9654:
9131:
8762:
8719:
8626:
8557:
8162:
7827:
in which the prevailing physical conditions allow molecules to form, including
7579:
7549:
7370:
7149:
6757:
6661:
6601:
6266:
5685:
for temperature. Single stars of known mass and composition follow predictable
5657:
4975:
4892:
3904:
3896:
3836:
3486:, and a right-handed convention. This system is convenient because most of the
3405:
3133:
2878:
2810:
of dust and debris orbiting its host star. It is created by collisions between
2454:
1936:
1711:
1521:
1224:
634:
356:
228:
13105:
12907:, where they can have a profound effect upon the evolution of the surrounding
12762:
10927:
10758:
9582:
9248:
7527:. This makes many meteor showers predictable events, as they recur every year.
7451:, usually as a long streak of light produced when such an object is heated to
6627:
6302:. Irregular moons are thought to be captured from other orbits, as opposed to
6286:
5916:
A critical mass below which an astronomical object cannot sustain its surface
5286:
5264:
5029:
4356:
4301:
3661:
3581:
3317:
2682:. At this rotation rate, mass can be readily lost from the equator, forming a
2379:
2095:
2048:
1910:
1773:
1147:
979:
805:
462:
17079:
16600:
14141:
14087:
14011:
13991:
13963:
13829:
13736:
13644:
13613:
13459:
13323:
12976:
12787:
12736:
12448:
12219:
11964:
11837:
11723:
11693:
11660:
11627:
11491:
11451:
11270:
11132:
10752:
10712:
10670:
10651:
10642:
10590:
10363:
10339:
10178:
10112:
9934:
formed from a glowing shell of expanding plasma that has been ejected from a
9418:
9320:
9174:
9148:
9105:
8904:
8784:
8756:
8744:
8619:
8553:
A compact and dense concentration of stars located at the center of a galaxy.
8526:
8470:
8366:
8341:
8174:
8158:
8103:
8021:
7497:
7452:
7378:
7184:
7120:
7108:
7068:
7031:
6881:
6829:
6280:
6124:
6054:
5742:
5617:
5450:
5333:
5000:
4904:
bound together by gravity. Galaxy clusters are distinct from similarly named
4878:
4836:
4736:
4698:
4677:
4381:
4038:
3995:. Atmospheric extinction varies by the wavelength of the radiation, with the
3987:
3695:
3655:
3500:
3141:
2913:
2839:, and artist's impressions of the disks' orientations around their host stars
2717:
2420:
2396:
2154:
1996:
1886:
1594:
1446:
1312:
1290:
1251:
1101:
1057:
1027:
920:
813:
15056:
14146:
12607:
11196:
11063:
The time that an object takes to complete a single revolution about its own
10490:
that differ by 90 degrees as viewed from a third body, e.g. when a planet's
10063:
9302:
9214:
9123:
9099:
9062:
9033:
8520:
8347:
7823:
6905:
6847:
6483:
6359:
6336:
5687:
5669:
5477:
to collect observational data about astronomical objects and events such as
5444:
4922:. Galaxy groups and galaxy clusters can themselves cluster together to form
4503:, as opposed to everything outside of the Milky Way, which is the domain of
4022:
3957:
3398:
3367:
3024:
2886:
2806:
2757:. During each day, the Earth's rotation causes every astronomical object to
2684:
1165:
970:
where evidence for an unseen orbiting companion is revealed by its periodic
821:
779:
primarily composed of dust and ice instead of mineral and rock are known as
657:
208:
16556:
16535:
16153:
14860:
14211:
13863:
13782:
13745:
13707:
13541:
13483:
13305:
13236:
13175:
12970:
12943:
12832:
12756:
12748:
12660:
12364:
12125:. Instead, the evidence for the binarity comes from shifts observed in the
12028:
11918:
11868:
11859:
11810:
11680:
11371:
11337:
11009:
10962:
10898:
10870:
10842:
10740:
10732:
10716:
10327:
10302:
10138:
10094:
10039:
9977:
9800:
9490:
9423:
9310:
9192:
9079:
8922:
8865:
8833:
8778:
8575:
8538:
8402:
8345:
of indistinct nebulosity. In modern usage, the term typically refers to an
8313:
8250:
8052:
7968:
7943:
7880:
7863:
7785:
7769:
7737:
7307:
7235:
7226:
7201:
7022:
6581:
6519:
6417:
6330:
6292:
6274:
6238:
vector, and which may be regarded as the weighted average of all planetary
6077:. The name originated from the fact that these planets orbit closer to the
5862:
5851:
5802:
5693:
5341:
5303:
4983:
4932:
4860:
4411:
4354:
while traveling from north to south each year. It is directly opposite the
4350:
4317:
4299:
while traveling from south to north each year. It is directly opposite the
4295:
4162:
3937:
3866:
3824:
3782:
3776:
3738:
3550:
3476:
3418:
3385:
3270:
3241:
3206:
2987:
2862:
2691:
2480:
2338:
2321:
2103:
1904:
1840:
1791:
1769:
1706:
1673:
1566:
1388:
1345:
1274:
1107:
1002:
938:
929:
913:
904:
895:
869:
625:
305:
14312:
14294:
14030:
13794:
13772:
13672:
13595:
13139:
13059:
12986:
12903:
12473:
12414:
12201:
11876:
11528:
11443:
11391:
11301:
11248:
11228:
Continuing, or changing in a non-periodic way, over a long period of time.
11071:
11065:
11015:
10997:
10910:
10702:
10379:
as they collide with each other and gradually coalesce into larger bodies.
10200:
9983:
9837:
is used in reference to a planet-like object that is not orbiting the Sun.
9770:
9764:
9740:
9648:
9474:
9449:
9442:
9242:
9020:
8990:
8928:
8581:
8189:
7292:
7250:
7036:
6853:
6807:, and which therefore represents the distance of the orbit's longest axis.
6803:
6621:
6230:
5950:
5824:
5796:
5790:
5754:
5548:
5426:
5389:
5212:
5162:
4955:
4872:
4854:
4533:
4323:
4262:
4216:
4009:
The branch of astronomy that studies objects and phenomena outside of the
3854:
3770:
3728:
3689:
3611:
3412:
3361:
2765:
2520:
2428:
1956:
1950:
1833:
1796:
1546:
1536:
1351:
1113:
675:
616:
by humans, often around the Earth but also around other bodies within the
596:
549:
16798:
16623:
15827:
15774:
14859:, U.S. Naval Observatory and H.M. Nautical Almanac Office, archived from
14597:
14219:
14108:
14100:
14006:
13970:
2. One of many hypothetical parallel universes which exist as
13625:
With reference to, or pertaining to, a point on the surface of the Earth.
13450:
13442:
13436:
13065:
13042:
13034:
13028:
12873:
12809:
12616:
12373:
12135:
12081:
12074:
12060:
as seen from Earth; or, equivalently, when the Sun's apparent geocentric
11970:
11850:
11796:
11714:
11672:
11616:
11568:
11379:
11260:
With reference to, or pertaining to, the geometric center of the Earth's
10936:
10878:
10827:
10746:
10680:
10586:
10517:
10504:
10349:
10160:
9947:
9710:
9685:
9675:
9528:
9495:
9413:
9397:
9254:
9166:
9117:
8873:
8838:
8770:
8532:
8515:
8075:
7728:
7693:
7671:
7531:
7394:
7175:
7027:
6954:: as the orbital positions of the Moon around Earth and Earth around the
6927:
6811:
6466:
6098:
5960:
5844:
5836:
5725:
5609:
5570:, i.e. the arithmetic mean position of all points within the approximate
5529:
5525:
5512:
5327:
5315:
5276:
5128:
of the Earth, i.e. the arithmetic mean position of all points within the
4965:, and galaxy groups and clusters can themselves cluster together to form
4961:
4830:
4802:
4716:
4521:
4417:
4364:
3996:
3992:
3258:
3183:
3124:
2869:
2844:
2798:
2700:
2537:
2406:
2362:
2309:
2216:
2158:
2024:
1698:
1602:
1303:
1257:
891:
682:
326:
166:
14512:
Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009),
14300:
14152:
13857:
13601:
13393:
13157:
13099:
13081:). The synodic day may be described as the time between two consecutive
13022:
11982:
11934:
11702:
11459:
11425:
11210:
in the medium. Most terrestrial scintillation effects are the result of
10774:
10563:
10110:. The term is most commonly applied to small bodies thought to exist in
9872:
9758:
9344:
9270:
9111:
8044:
7773:
is not a minor planet because it orbits another body instead of the Sun.
7593:
7429:
7280:
7274:
7256:
6841:
6709:
5856:
5309:
5259:
4154:
3848:
3788:
3616:, with the larger body located at one of the focal points of the ellipse
3587:
3482:
3299:
3165:
3107:
3037:
2759:
2270:
2042:
1436:
1176:
584:
525:
342:
16593:
16570:
16050:
15470:, Oxford Quick Reference Online (3 ed.), Oxford University Press,
14769:
14215:
13820:
13637:
13467:
13370:
13248:
12858:
12478:
12266:
of an object in a vacuum near the surface of the Earth, as a result of
12068:
11990:
11976:
11926:
11732:
11362:
11348:
11207:
11107:
or other localized activity across the line of sight. Examples include
11048:
10675:
10578:
10419:
9087:
9056:
9027:
8804:
8796:
8790:
8137:
8079:, they have since moved too far apart to be gravitationally bound as a
7892:
7707:
7635:
7607:
7566:
7562:
7515:. These are produced by debris left over from a larger body, such as a
7212:
7153:
6962:
6861:
6769:), where the center part of the disk appears brighter than the edge or
6700:
6531:
6452:
6381:
6248:
6240:
6084:
5782:
5705:
5681:
5542:
5479:
5401:
5072:
4967:
4924:
4918:
4912:
4866:
4587:
4539:
4463:
4433:
4425:
4335:
4274:
4256:
3978:
3860:
3544:
3515:
3249:
3245:
3229:
3215:
3067:
2747:
2584:
2472:
2436:, while the modern demarcation of their borders was established by the
2401:
2303:
2255:
2162:
2150:
2030:
1847:
1720:
1715:
1648:
1640:
1514:
1470:
1430:
1407:
1320:
1295:
988:
966:
737:
279:
with characteristics indicating that the luminosity is not produced by
180:
174:
14036:
13788:
13607:
13477:
13093:
12795:
of hydrogen nuclei can be sustained (equivalent to approximately 0.08
12696:
12654:
12402:
12338:
12159:
11894:
11784:
11604:
11598:
11477:
11431:
11306:
11083:
10916:
10884:
A disk- or ring-shaped accumulation of various solid material such as
10616:
10434:
10375:
10176:
of the body being orbited during each revolution. It therefore has an
10172:
in which the orbiting object passes directly over or nearly over both
10152:
10146:
10057:
10033:
9906:
9894:
9829:
9642:
9472:
A unit of length defined as the distance at which a star would show a
9385:
9373:
9276:
9220:
9160:
8843:
8821:
8689:
8410:
8377:
8268:
8081:
7994:
7976:
7961:
7955:
7910:
7806:
7791:
7646:
7286:
7060:
7048:
6950:
6537:
6513:
6458:
6304:
6037:
5993:
5872:
but additionally taking into account the terrain and the depth to the
5635:
5321:
5110:
5088:
4906:
4722:
4492:
The branch of astronomy that studies objects and phenomena within the
4393:
4194:
4148:
4102:
4087:
4054:
or any objects larger than a star or the Solar System itself, such as
4044:
3701:
3575:
3454:
3373:
3079:
3073:
3030:
3018:
2981:
2943:
2925:
2892:
2890:
formed from gas ejected from a central star that now follows a nearly
2812:
2606:
2350:
2122:
2066:
1219:
1159:
1119:
972:
853:
827:
799:
759:
753:
663:
651:
618:
16688:
16015:
15011:, vol. 79, Dordrecht, D. Reidel Publishing Co., pp. 51–60,
14800:"Distance & Speed Of Sun's Orbit Around Galactic Centre Measured"
13971:
13713:
13475:
between an astronomical body and its gravitational partner. When the
13430:
13379:
13299:
13256:
13183:
13133:
13077:
12949:
12917:
12803:
12622:
12505:
12396:
12314:
12199:
which is used to locate the positions of astronomical objects on the
12119:
system where the individual components have not been resolved with a
12115:
11952:
11832:
11688:
11635:
11592:
11562:
11554:
11516:
11465:
11437:
11385:
11312:
11077:
10950:
10944:
10886:
10865:
10820:
10468:
10440:
10392:
10321:
10295:
10204:. For the Earth in particular, this phenomenon is referred to as the
10130:
10118:
10021:
9784:
9746:
9535:
9479:
9260:
8648:
8455:
8442:
8375:
that could not be resolved into their individual components, such as
8353:
8209:
7627:
7571:
7475:
7459:
7113:
7103:
7054:
6996:
6980:; when the illuminated portion is becoming smaller, it is said to be
6715:
6670:
6447:
5985:
5930:
5814:
5717:
5699:
5675:
5586:
5485:
5470:
5190:
5080:
5054:
5049:
5034:
4996:
4848:
4842:
4792:
4744:
4595:
4189:
4132:
3647:
3539:
3276:
3264:
3198:
2975:
2830:
2634:
2614:
2591:
2557:
2514:
2433:
2344:
2223:
2036:
1990:
1962:
1827:
1731:
1628:
1610:
1524:
about which any two or more bodies of a gravitationally bound system
1505:
1285:
1243:
1197:
886:
529:, one of the two extreme points of distance between the body and its
391:
384:
39:
35:
13976:
13814:
13697:
13569:
A measure of the orbital motion of a relatively small body (e.g. an
13535:
13471:
such that, over the course of an orbit, there is no net transfer of
13317:
13111:
12925:
12897:
12891:
12797:
12573:
12571:
scheme is a two-dimensional classification based on temperature and
12394:
that orbit each other, bound by gravitational attraction, such as a
12332:
12211:
11610:
11413:, which instead reckons time based on the Sun's position in the sky.
11335:
The precise time of year on Earth when the Sun appears to cross the
11097:
11035:
10557:
10524:
10492:
10260:
9940:
star late in its life. The name derives from their resemblance to a
9669:
9484:
9338:
8934:
8723:
when estimating the shape and characteristics of the object's orbit.
8657:
8587:
8371:
8325:
8129:
8109:
7664:
7613:
7483:
7447:
7268:
7199:
The precise time of year on Earth when the Sun appears to cross the
7134:
7076:
7042:
6743:
6393:
6224:
6189:
5924:
5918:
5748:
5651:
5623:
5491:
5449:, distorting the light from a much more distant blue galaxy into an
5361:
5355:
5230:
5224:
4657:
4581:
3943:
3846:
is either 0 degrees or 180 degrees. The two equinoxes, known as the
3736:. The plane of the Earth's terrestrial equator is the basis for the
3424:
3391:
3085:
2356:
2018:
1859:
1814:
1718:
in its core, with the latter being a characteristic of stars on the
1622:
1498:
1339:
415:
321:
271:
248:
220:
186:
15844:
15195:
14966:
14921:
14498:
13909:
13842:
13766:
13521:
13405:
13387:
13284:
13231:
13151:
13117:
12931:
12862:
12730:
12467:
12323:
12301:
12126:
12121:
12042:
12001:
11762:
11535:
11522:
11409:
11162:
11103:
10723:
10636:
10357:
10051:
9936:
9350:
8750:
8391:
8358:
8097:
7985:
7898:
7700:
7652:
7619:
7587:
7557:
7538:
7511:
7489:
7423:
7262:
6899:
6791:
6443:
6170:
6129:
6118:
6088:
6014:
5998:
5966:
5874:
5746:
within which its gravitational attraction dominates the motions of
5711:
5571:
5395:
5218:
5168:
5144:
5093:
5066:
5060:
5048:
A cataclysmic event that generates a brief but intense outburst of
5023:
4884:
4808:
4760:
4728:
4599:
4564:
4527:
4494:
4455:
4387:
4230:
A term used to classify the brightest stars in the night sky, with
4210:
4011:
3716:
The imaginary line on a gravitationally rounded spheroid such as a
3326:
3171:
2937:
2857:
2787:
typically refers to the time at which the upper culmination occurs.
1876:
1806:. On Earth, the plane of the celestial equator is the basis of the
1588:
1580:
1399:
1217:
A unit of length used primarily for measuring distances within the
1188:
1182:
793:
787:
745:
731:
590:
537:
439:
424:
15949:
15690:
13980:, which itself comprises all of space and time and their contents.
13770:
and the current position of an orbiting body as it moves along an
13678:
13571:
13242:
12690:
12561:
11958:
11906:
11586:
11483:
10835:
10045:
9613:
9559:
9428:
9389:
were absent, i.e. the orbit that coincides with the instantaneous
9208:
8994:, the eccentricity ranges from greater than zero to less than one.
8695:
8297:
8123:
7705:
is visible in dark skies on clear nights, in the direction of the
7441:
7392:
between 1771 and 1781. The Messier catalogue includes most of the
7360:
distance at those times, with the intention of obtaining accurate
7350:
7116:, although this can vary depending on sky conditions and eyesight.
6797:
6495:
6195:
6023:
5922:
through nuclear fusion. This mass limit, equal to about 7% of the
5868:
5808:
5497:
4949:
3879:
3722:
that represents the intersection of the spheroid's surface with a
3470:
2753:
2646:
2622:
2445:
2054:
1927:
1853:
1820:
1477:
above the horizon, it defines an object's current position in the
1434:. Axial tilt usually does not change considerably during a single
1383:
1361:
1261:, the origins of those objects and phenomena, and their evolution.
1171:
1051:
847:
594:, measured in the direction of motion. It is one of six canonical
543:
16794:
15337:
Hut, P. (June 1981), "Tidal evolution in close binary systems.",
13719:
13489:
13162:
13082:
13071:
13016:
12867:
12309:
11296:
11216:
11041:
10892:
10810:
10768:
10285:
10184:
10003:
9998:
9814:
9694:
9630:
9568:
9552:
9379:
9295:
9284:
9198:
8964:
8899:
8713:
8591:, which is a similar but longer-term change in axial orientation.
8465:
8415:
8369:. Historically, it was also used to refer to extended sources of
8201:
8038:
7922:
7798:
7344:
6593:
6507:
6439:
6298:
6093:
6032:
5762:
5270:
5101:
4988:
4669:
4192:
to a group of physically associated stars under study, such as a
3818:
3810:
3802:
3764:
3710:
3604:
3598:
3431:
3253:
3090:
2897:
2775:
2674:
The surface velocity at the equator of a rotating body where the
2286:
1802:
1463:
1424:
1299:
1281:
1193:
1153:
1061:
are often used interchangeably, there are technical distinctions.
1031:
that is a single, tightly bound, contiguous structure, such as a
836:
770:
531:
501:
469:
432:
372:
15869:
Stellar Interiors: Physical Principles, Structure, and Evolution
14182:
13937:
13925:
13583:
13515:
13345:
13195:
13189:
13145:
12909:
12849:
12442:
12420:
12408:
12312:
which, for at least a portion of its life, radiates energy into
12022:
12016:
11888:
11802:
11653:
11343:
11148:
10904:
10549:
A distant, point-like energy source originating from a powerful
10369:
10102:
10027:
9971:
9942:
9888:
9882:
9847:
9589:
9456:
9054:
around an astronomical body, expressed as the angle between the
8910:
8482:
8383:
8262:
8195:
7949:
7902:, though its orbital position with respect to the Earth and the
7757:
7640:
7505:
7467:
7356:
7330:
7207:
7082:
6982:
6976:
6875:
6749:
6737:
6501:
6165:
5944:
5854:
drawn upon the celestial sphere that passes through both of the
5830:
5774:
5520:
5349:
5174:
4900:
4780:
4754:
4704:
4645:
4569:
4499:
4471:
4170:
4081:
4056:
4016:
3872:
3718:
3639:
3534:
3488:
3153:
2955:
2949:
2735:
2508:
2083:
1898:
1558:
1131:
1125:
1039:
741:
or it may be composed of stars from more than one constellation.
697:
364:
311:
265:
214:
212:
the star would show if it were located at a distance of 10
16718:
14322:, and visible planets appear to travel across a band of twelve
14280:
14233:
14210:. They are usually produced when a high-mass object, usually a
13946:
13942:
13577:
13010:
12854:
12766:
that orbits another natural satellite, i.e. "a moon of a moon".
12471:, usually in the context of some region of interest within the
12426:
12327:
12034:
11997:
11912:
11824:
A standard unit of distance equal to the radius of the Earth's
10535:
10426:
10168:
10009:
9805:
9792:
9636:
9465:
9332:
9236:
9186:
9154:
9093:
9050:
9006:
8984:
8958:
8707:
8701:
8510:
8362:
8333:
8303:
8256:
8166:
7763:
7745:
7542:
7523:
7517:
7435:
7402:
7384:
7128:
6970:) and completely darkened by the Moon's own shadow (known as a
6835:
6785:
6587:
6434:
6387:
6174:
6154:
6069:
An archaic term that is sometimes used to refer to the planets
6028:
6018:
6010:
6006:
6002:
5532:
5383:
5377:
5105:
5097:
4898:
A large-scale structure consisting of hundreds or thousands of
4816:
4710:
4437:
that undergoes sudden, dramatic increases in brightness due to
3909:
3468:
defined by the plane of Earth's orbit around the Sun (i.e. the
2627:
2595:
2282:
2254:
around the cometary body. Sometimes a comet can produce a long
2060:
1881:
1656:
1573:
1572:
The process by which the class of subatomic particles known as
1544:
of each body and the distances between them. For example, in a
1526:
1441:
1105:
but is a more complex, less cohesively bound structure than an
781:
612:
578:
519:
448:
293:
236:
15435:
14318:
14264:
14122:
13999:
13931:
13509:
13495:
13351:
13339:
13271:
13161:, a result of the fact that both the body being studied (e.g.
13087:
12937:
12684:
12555:
12530:
12499:
12461:
12390:
11842:
11830:(typically measured from the Sun's center to the layer in the
11806:. Prominences may be hundreds of thousands of kilometers long.
11768:
11647:
11262:
11202:
11003:
10510:
10015:
9774:
are all commonly used as reference planes in various contexts.
9576:
9109:; in some contexts, the two nodes may be distinguished as the
8916:
8837:. It is thought to be divided into two regions: a disc-shaped
8634:
8622:, it is typically used to compare phase differences over time.
8573:
A continuous, gravity-induced change in the orientation of an
8488:
8476:
8069:
8001:
7886:
7658:
7362:
7272:
which a fictitious body would have if it moved in a perfectly
7088:
6944:
6919:
6869:
6827:
The angle between a specified reference direction, called the
6678:
6159:
5663:
4824:
4399:
4184:
4126:
4050:
3931:
3223:
3191:
3159:
2919:
2741:
2729:
1892:
1616:
1552:
1367:
1045:
1033:
996:
725:
703:
456:
281:
242:
202:
14316:
over the course of the year as observed from Earth. The Sun,
14306:
14288:
14241:
14207:
13916:
13691:
13311:
13201:
13167:
13057:
The time it takes for an object to rotate once about its own
12482:
12056:
12050:
12010:
11946:
11940:
11882:
11826:
11790:
11748:
11641:
11580:
11574:
11507:
11471:
11403:
11397:
10582:
10498:
9680:
9606:
9327:
9289:
9280:
8892:
8827:
8460:
8450:
8424:
8319:
8308:
8181:
7904:
7751:
7677:
7328:
and passing through the point directly overhead known as the
7324:
7158:
6956:
6890:
6765:
6542:
6525:
6079:
6074:
5629:
5592:
5566:
5149:
4786:
4446:
4405:
4397:
which do. The fixed stars are typically taken to include all
4344:
4342:, the First Point of Libra represents the point at which the
4289:
4142:
3830:
3758:
defined by an origin at the geometric center of the Earth, a
3706:
interval, with a given epoch as the temporal point of origin.
3667:
3633:
3460:
3355:
3235:
3147:
2723:
2600:
2502:
2466:
2242:
2234:
1984:
1944:
1373:
765:
709:
511:
408:
15984:
15597:, Center for Computational Physics in Hawaii, archived from
11782:
A large, bright, transient feature, often in the shape of a
10484:
A configuration in which two celestial bodies have apparent
7366:
positions which are self-consistent over large areas of sky.
6966:
Earth alternates between completely illuminated (known as a
4441:
on its surface. This change in brightness occurs across the
3591:, which have eccentricity equal to 0), or one with negative
1948:
at which a hypothetical indefinite extension of the Earth's
1145:
Any abstract pictorial symbol used to represent one or more
15102:(Third ed.), Imagine Publishing Limited, p. 151,
14906:
14476:
13920:
13181:
The calculation of the passage of time based on successive
12294:
9690:
9482:
as observed from Earth's orbit. It is equal to 3.2616
9274:
are related by a ratio of small integers. For example, the
9127:, which is coplanar with the reference plane, has no nodes.
7872:
7487:. If it survives to reach the surface, it is then termed a
6894:
6818:
6103:
6027:
with freezing points above 100 K (−173 °C), e.g.
2769:, creating two points at which it crosses the meridian: an
2552:
2165:
1541:
832:
497:. The brighter the object appears, the lower its magnitude.
348:
34:
is a list of definitions of terms and concepts relevant to
12791:
whose mass is smaller than the smallest mass at which the
12566:
12054:
reaches its most northerly or most southerly point in the
11383:
of an object (e.g. the Earth) with respect to the distant
9574:
The point at which a body orbiting the Earth (such as the
8962:. For a binary system, it is typically presented from the
2773:, at which the object reaches its highest point above the
1690:
generated by a rapidly spinning star matches the force of
912:, and how humans might be able to detect extraterrestrial
454:
The point at which a body orbiting the Earth (such as the
16792:
16160:
15902:
A Knowledgebase for Extragalactic Astronomy and Cosmology
12823:
11746:
A standard unit of mass equal to the mass of the Earth's
11500:
11487:, as viewed from a given location on the Earth's surface.
9013:
7080:, interacts with the magnetic field of a body, such as a
7074:
A mostly convex region formed when a plasma, such as the
6134:
5188:
The ratio of the brightness of an astronomical body at a
3947:
that a star will have during part or all of its lifetime.
3941:. This curve predicts the combination of temperature and
1491:
430:
The point at which an orbiting body is furthest from its
14900:
14292:
that extends approximately 8 degrees north or south (in
12853:
that orbit further from the Sun than the Earth, such as
12274:
generated by its rotation. It is by definition equal to
11295:
One half of the longest diameter (the major axis) of an
7878:
The solid, rocky body that orbits the Earth as its only
6374:
A unit of time defined as exactly 365.25 days of 86,400
5381:
which are gravitationally bound to each other and which
4475:
having a size between 1.5 and 2 times that of the Earth.
3840:); or, equivalently, when the Sun's apparent geocentric
3834:(i.e. the two points at which this plane intersects the
2285:
around the Sun is very nearly 5/2 the orbital period of
2081:
Any very large concentration of mass at the center of a
1982:
An imaginary sphere that encompasses the Earth's entire
1760:
A star used for calibration of high-powered teleescopes.
15176:
Publications of the Astronomical Society of the Pacific
12664:
over time based upon its mass and chemical composition.
12139:
of the components change over the course of each orbit.
11700:. The Sun's faculae are most readily observed near the
10694:
A conspicuous trail of enlarged red stars found on the
10589:
and optical spectra are characterized by strong, broad
7284:
as the actual body in its elliptical orbit. Unlike the
6619:. The phenomenon is the basis for the stable orbits of
5375:
A tight, spherical conglomeration of many thousands of
3601:, and are very common in two-body astronomical systems.
3458:, with an origin at the geometric center of either the
2268:
A property of two objects orbiting the same body whose
1151:, events, or theoretical constructs, e.g. those of the
190:, and have surface temperatures of 7,600–10,000 kelvin.
15244:, New York: McGraw-Hill Book Company, pp. 70–124.
14511:
14116:. A white dwarf lacks the mass needed to continue the
12412:
are also star systems. Star systems are distinct from
11526:, the term "sky" is also used as another name for the
10942:
The distance from an astronomical object at which the
9550:
The point at which an orbiting body is closest to its
7908:
causes its visibility to change in a regular cycle of
7011:
6867:
The total amount of energy emitted per unit time by a
5469:
which analyzes minute distortions in the curvature of
4667:, and the brightest such active galaxies are known as
2896:
around it. This type of disk can be found around many
785:; bodies less than one meter in diameter are known as
14661:
14582:
13075:
it is orbiting (rather than to the much more distant
11766:. It is commonly used to express the masses of other
11156:
of a more massive and luminous host galaxy; e.g. the
11136:
was first noted by American astronomer Stephen Saber.
10459:
A method of computing the mean strength of a varying
9416:
expanse that exists beyond the Earth and between all
8681:
The duration of time between the earliest and latest
7481:
A small rock or boulder that has entered a planetary
4720:. Estimates of the duration of one revolution of the
4531:, as viewed from Earth; considered as a point on the
4519:
The direction in space that is directly opposite the
2437:
1556:
is significantly larger than the mass of an orbiting
15759:
15363:
14090:
for a star compared to standard stars with the same
13581:) with respect to a larger, perturbing body (e.g. a
13487:
orbits with the same face always pointed toward its
12611:; or another name for the stellar atmosphere itself.
12485:
could be defined as encompassing some or all of the
11932:
The calculation of the passage of time based on the
11457:
The calculation of the passage of time based on the
10025:. In general, planetary systems include one or more
9751:
9640:
characteristics of the body such that the idealized
6960:
change, the visibility of the side of the Moon that
3022:
at which an orbiting object moves south through the
2563:
668:
655:
at which an orbiting object moves north through the
15675:
15402:
15041:(2nd ed.), New York: Oxford University Press,
13193:(i.e. successive returns of the object to the same
12847:An archaic term that is sometimes used to refer to
12477:. For example, the starfield surrounding the stars
12465:visible in an arbitrarily sized field of view of a
6686:. It can allow normally hidden parts of the Moon's
5596:; centered upon the Sun, e.g. a heliocentric orbit.
5178:
as defined with respect to the center of the Earth.
5152:; centered upon the Earth, e.g. a geocentric orbit.
3753:
3447:
1831:A diagram of the relationships between the Earth's
1280:The branch of astronomy that employs principles of
535:– either the point of minimal distance, called the
14718:
14422:Physics, Formation and Evolution of Rotating Stars
13588:
13240:that is perpendicular to the line of sight of the
11788:, consisting of plasma extending outward from the
10954:. Outside this limit, loose material will tend to
10198:Any slow change in the orientation of an object's
10182:equal or nearly equal to 90 degrees to the body's
9287:, such that Pluto completes two orbits around the
9060:or axis of direction of the orbiting object and a
7537:A measure of the abundance of elements other than
6735:). Though the light-year is often used to measure
6600:of orbital motion, and (in certain scenarios) the
5633:. The heliosphere encompasses the entirety of the
4287:of (0°, 0°) and represents the point at which the
3514:(of a star or planet) The temperature of an ideal
610:An object that has been intentionally placed into
329:and geological or environmental surface features).
15366:Monthly Notices of the Royal Astronomical Society
15303:
14585:Monthly Notices of the Royal Astronomical Society
14453:Astronomical Observations, An Optical Perspective
14268:which have finished contracting and have reached
14262:achieved by newly formed, chemically homogeneous
12880:
12048:Either of the two precise times of year when the
11542:
11075:. It is not necessarily the same as the object's
10859:
9164:, the orbital period is often referred to as the
8036:The horizontal angular distance between the rise
7509:that seemingly radiate from a single area in the
5058:away. The source of most GRBs is theorized to be
5052:radiation which can be detected from billions of
4916:and from smaller aggregates of galaxies known as
3256:. Confusingly, the term has also come to include
3100:
2851:
1967:
1807:
17077:
15570:, Universitätsverlag Göttingen, pp. 54–59,
15068:
14945:
14257:
14247:
14046:
13337:The line that divides the illuminated side of a
11013:. Such objects have often been ejected from the
10814:. The direction of rotation is determined by an
10695:
10289:. The direction of rotation is determined by an
10205:
9377:that an orbiting object would follow around its
7260:that has elapsed since the orbiting body passed
7139:
6323:
6106:, which appear to move independently of the Sun.
5899:
5772:perpendicular to a line from an observer to the
5194:of zero to an idealized flat, fully reflecting,
4947:A gravitationally bound aggregation of up to 50
4732:range from 225 to 250 million terrestrial years.
4328:
4267:
3924:
3682:
3378:
1392:
839:that is occupied by numerous irregularly shaped
254:
13652:
12061:
11475:. The fundamental unit of sidereal time is the
11347:passage. It represents the moment at which the
10485:
9822:
9604:The point at which a body orbiting the Earth's
7211:passage. It represents the moment at which the
6763:An optical effect seen in stars (including the
5455:
5424:Any very large distribution of mass, such as a
4655:which, when active, can generate a much higher
4282:
3841:
3744:
3297:A hotter and more massive star, in contrast to
2929:. The classification is used mostly in amateur
2411:
2110:
2072:
2052:that typically exhibit characteristics of both
1725:
541:, or the point of maximal distance, called the
406:The point at which a body orbiting the Earth's
234:A roughly circular mass of diffuse material in
54:
15728:
15493:HubbleSOURCE: Constellation Mythological Forms
15408:
14873:
14724:
14470:
12740:detectable at submillimetre wavelengths (i.e.
11506:Everything that lies above the surface of the
10404:
10224:
10069:
9004:The set of parameters that uniquely define an
8819:A vast theoretical cloud of predominantly icy
8430:
8101:based on the acquisition of information about
7298:
5641:
3762:created by projecting the Earth's terrestrial
2997:, such that normal atoms cannot exist in them.
2620:Any model concerning the origin of either the
2487:
1724:. Brown dwarfs can still generate energy from
1626:. The term is often used interchangeably with
1337:A slow, continuous, gravity-induced change (a
16778:
16000:
15865:
15309:
14637:
14399:, Cambridge, UK: Cambridge University Press,
14396:Cambridge Illustrated Dictionary of Astronomy
14326:within this belt as the Earth orbits the Sun.
12935:stellar explosion occurring during a massive
11846:and astronomical objects relative to the Sun.
11772:and astronomical objects relative to the Sun.
11341:, while generally trending southward at each
9788:of an orbital plane of a distant star system.
8776:A celestial event that occurs when a distant
8742:The practice and study of directly observing
8544:
8173:that are radio sources and display prominent
7266:, expressed as the angular distance from the
7205:, while generally trending northward at each
6903:. Luminosity is related to but distinct from
6406:
5778:that passes through the point of observation.
5331:equal to 35,786 kilometres (22,236 mi);
5292:
4604:
3985:by matter (dust and gas) between an emitting
3653:A list or table of the expected positions of
3438:
2500:and the accompanying magnetic field from the
2205:
2198:
1800:that is coplanar with the body's terrestrial
206:'s absolute brightness. It is defined as the
15968:"Glossary of (comet and) astronomical terms"
15866:Hansen, Carl J.; Kawaler, Steven D. (1999),
15567:3D-Spectroscopy of Dense Stellar Populations
15530:
15357:
15210:
15071:Astronomy and Astrophysics Supplement Series
14655:
14192:, yet displays an anomalous level of excess
14187:
13547:
13252:and its measured distance from the observer.
13091:), which is not necessarily the same as the
12968:experienced at the equatorial surface of an
12194:
11950:. The fundamental unit of solar time is the
11899:
11692:of the Sun that form in the canyons between
10678:into space. These objects are the basis for
10568:
10550:
10123:
9912:
9017:A diagram showing four of the six canonical
8800:eclipses are specific types of occultations.
8717:), and therefore result in a high degree of
8687:made by astronomers of an object within the
8682:
8493:
8307:, whose orbit brings it into proximity with
8290:
8273:
8087:
7398:easily visible from the Northern Hemisphere.
7144:. These stars are characterized by being in
7026:that might explain the apparent presence of
6488:
6244:and rotational planes comprising the system.
6144:
5464:
5337:are a special case of geosynchronous orbits.
4662:
4650:
4574:
4504:
4236:
3592:
3493:
2930:
2575:cosmic microwave background radiation (CMBR)
2313:parameters, which may suggest that they are
2301:. That is, either they have nearly the same
2088:
2011:
1294:and phenomena, examining properties such as
840:
791:; very large asteroids are sometimes called
774:
15956:, Space Telescope Science Institute (STScI)
15812:
15729:Jaschek, Carlos; Jaschek, Mercedes (1990),
15722:
15669:
15642:
15611:
15457:
15276:
15062:
15000:
14755:
14576:
14549:
14505:
14456:, Cambridge University Press, p. 109,
14091:
13974:disconnected constituent parts of a larger
13833:
12097:
11395:(rather than to its primary star, e.g. the
10453:
9234:The situation that occurs when two or more
8831:at distances ranging from 2,000 to 200,000
8639:
8004:Morgan–Keenan stellar classification system
7914:when viewed from the Earth. The adjectival
7833:
7569:. Micrometeorites are a major component of
5691:across this chart over the course of their
5673:may be substituted for luminosity, and its
5166:by a straight line that passes through the
4773:
4557:
3094:
2992:
1201:
1055:. Though the terms astronomical "body" and
769:at a distance no greater than the orbit of
735:. An asterism may form part of an official
16785:
16771:
16007:
15993:
15859:
15557:
15429:
15289:, Cambridge University Press, p. 87,
15233:
15167:
15030:
15028:
15026:
14951:
14879:
14728:Evolution of stars and stellar populations
14725:Salaris, Maurizio; Cassisi, Santi (2005),
14562:, Cambridge University Press, p. 80,
13850:
13670:1. The passage of a particular
13398:
12814:
12720:
12637:
12087:
11665:
11021:
10990:
10864:, the celestial equivalent of terrestrial
10373:; they are thought to form out of smaller
10031:, though such systems may also consist of
9899:
9876:that is geologically differentiated or in
9634:alone, or any force which complicates the
9158:around another object. For objects in the
8761:
8734:
8718:
8280:
7681:orbits with a period of 240 million years.
6719:: approximately 9.46 trillion kilometres (
5656:
4766:
4001:
3999:being greater for blue light than for red.
3835:
3404:
3196:which they may form a co-moving pair or a
2985:. These stars are in an advanced state of
2856:, the celestial equivalent of terrestrial
2368:
2250:on a comet's surface, producing a visible
1495:Two bodies of similar mass orbit a common
15826:
15773:
15689:
15537:Andersen, J. (2000), Livio, Mario (ed.),
15385:
15316:, Cambridge University Press, p. 4,
15115:
14983:
14965:
14920:
14683:
14640:The Facts on File Dictionary of Astronomy
14614:
14596:
14540:
14443:
13885:
13599:of each body, including the small body's
13499:, which is tidally locked with the Earth.
13104:
12953:is triggered into runaway nuclear fusion.
12761:
12666:
12536:
11996:A stream of charged particles, primarily
11696:. They are produced by concentrations of
10926:
10757:
10496:is perpendicular to the direction of the
9581:
9247:
7521:, and hence they follow roughly the same
6626:
6285:
6179:
5997:composed mainly of elements heavier than
5910:
5584:With reference to, or pertaining to, the
5407:
5285:
5263:
5142:With reference to, or pertaining to, the
5100:gases rather than heavier elements, e.g.
5028:
4822:A large, gravitationally bound system of
4355:
4300:
3699:, because such quantities are subject to
3660:
3597:. Elliptical orbits take the shape of an
3580:
3518:that would emit the same total amount of
3316:
2816:. A debris disk can be discerned from an
2526:
2378:
2094:
2047:
1909:
1632:, though the latter can also refer to an
1440:; Earth's axial tilt is the cause of the
1208:
1146:
1063:
978:
804:
461:
299:A measure of the proportion of the total
46:and phenomena that originate outside the
15806:
15753:
15655:, Springer Theses, Springer, p. 9,
15536:
15141:
15095:
14847:
14845:
14843:
14841:
14839:
14555:
14412:
14388:
14386:
14384:
14382:
14272:, with energy being derived solely from
13962:
13800:
13643:
13636:
13612:
13368:
13357:
13322:
13115:; Earth's synodic day is often called a
12975:
12786:
12735:
12150:
11963:
11659:
11131:
11089:
10908:. Ring systems are common components of
10834:
10751:
10669:
10641:
10516:
10362:
10319:and estimated distance. For planets and
10177:
10111:
9904:, but excluding smaller objects such as
9508:
9441:
9417:
9330:at which an astronomical body or object
9301:
9147:
9104:
9012:
8982:A parameter that determines how much an
8903:
8783:
8755:
8743:
8525:
8469:
8340:
8102:
7686:
7611:that undergoes very small variations in
7377:
7107:
6988:
6880:
6828:
6682:as seen from the Earth, a result of the
6633:
6279:
6222:The imaginary plane passing through the
6123:
6053:
5741:
5616:
5441:A luminous red galaxy (LRG) acting as a
5436:
5332:
5039:
4877:
4835:
4697:
4602:, where the Milky Way appears brightest.
4380:
4037:
3986:
3949:
3694:
3654:
3603:
3506:
3499:
3397:
3140:
2912:
2902:
2822:
2716:
2464:that surrounds cooler stars such as the
2395:
1995:
1885:
1826:
1593:
1490:
1445:
1311:
1289:
1250:
1100:
1056:
1026:
857:. The asteroid belt is often called the
555:
331:
15648:
15463:
15254:
15216:
15089:
15034:
15023:
15006:
14837:
14835:
14833:
14831:
14829:
14827:
14825:
14823:
14821:
14819:
14761:
14638:Daintith, John; Gould, William (2009),
14145:
13967:, whose size it is possible to measure.
13377:
12606:
12105:
11195:
10309:
10062:
9809:the Sun, which is massive enough to be
9218:for the orbits of other objects in the
9213:
9122:
9098:
9061:
9032:
8988:deviates from a perfect circle. For an
8974:
8519:
8346:
7822:
6904:
6846:
6535:but far larger, and is home to several
6482:
6358:
6335:
5904:, these stars are positioned where the
5686:
5668:
5443:
5132:that is the precise shape of the Earth.
4537:, the Milky Way's anticenter is in the
4307:
4281:, the First Point of Aries defines the
4222:
4048:. The term is generally not applied to
4021:
3956:
3825:extended indefinitely in all directions
3366:
3023:
2885:
2805:
2683:
2291:
1710:that is too low in mass to sustain the
1164:
845:ranging in size from dust particles to
820:
656:
602:
466:) is furthest from the Earth. Contrast
382:belonging to the more general class of
285:. A galaxy hosting an AGN is called an
207:
14:
17078:
16900:Electrical and electronics engineering
16885:Developmental and reproductive biology
15617:
15563:
15540:Unsolved Problems in Stellar Evolution
15282:
15239:
15173:
14449:
14425:, Astronomy and Astrophysics Library,
14418:
14392:
14132:
14016:
13862:
13781:
13706:
13627:
13540:
13482:
13304:
13235:
13224:
12984:(m/s) or as a multiple of the Earth's
12969:
12955:
12942:
12755:
12678:generated by the convective motion of
12659:
12579:
12176:
12027:
11917:
11858:
11686:Solar faculae are bright spots in the
11336:
11101:of a star to vary as rotation carries
11008:
10897:
10869:
10841:
10739:
10474:measurements taken at different times.
10463:. It is determined by calculating the
10381:
10326:
10301:
10038:
9976:
9799:
9489:
9356:
9309:
9283:exists in a stable 2:3 resonance with
9191:
9040:
8921:
8832:
8777:
8725:
8574:
8537:
8312:
8249:
7967:
7942:
7879:
7862:
7784:
7768:
7382:, 103 of which were catalogued as non-
7322:A line running north–south across the
7306:
7225:
7200:
7106:scale indicating the brightness of an
7021:
6783:The imaginary line connecting the two
6580:
6579:Any of a set of points near two large
6518:
6329:
6291:
6273:
5974:systems are examples of hypergalaxies.
5861:
5860:and is therefore perpendicular to the
5801:
5692:
5621:which surrounds and is created by the
5302:
5236:
5013:
4982:
4859:
4772:A star or cluster's distance from the
4748:experienced by objects subject to the
4511:
4410:
4349:
4316:
4294:
3936:
3865:
3823:
3781:
3775:
3737:
3549:
3475:
3417:
3384:
3269:
3240:
2986:
2861:
2690:
2337:
1988:and is stationary with respect to the
1942:One of two coordinates in the Earth's
1903:
1866:
1839:
1705:
1672:
1344:
1137:
1106:
1082:
1001:
928:
903:
831:located roughly between the orbits of
624:
304:
16766:
15988:
15621:Formation and Evolution of Exoplanets
15007:Einasto, J. (1978), "Hypergalaxies",
14427:Springer Science & Business Media
14379:
14311:
14293:
14029:
13793:
13771:
13671:
13594:
13187:of an astronomical object, such as a
13138:
13058:
12985:
12902:
12568:Morgan–Keenan spectral classification
12511:
12472:
12413:
12200:
11875:
11527:
11442:
11390:
11359:in the Southern Hemisphere. Contrast
11300:
11247:
11070:
11064:
11014:
10996:
10909:
10701:
10514:at its first and last quarter phases.
10199:
9982:
9769:
9763:
9739:
9717:
9699:
9647:
9473:
9460:as seen from the Earth (not to scale)
9454:shift of a star at a distance of one
9448:
9241:
9019:
8989:
8927:
8580:
8500:
8188:
7336:
7291:
7249:
7223:in the Southern Hemisphere. Contrast
7035:
6852:
6802:
6620:
6229:
6157:that exists in the space between the
6108:
5949:
5823:
5795:
5789:
5753:
5667:; depending on the usage, the star's
5547:
5425:
5416:
5388:
5211:
5204:
5172:and an observer; i.e. the observer's
5161:
4954:
4871:
4853:
4532:
4484:
4322:
4261:
4215:
4208:The first use of a newly constructed
4152:) are most readily observed near the
3915:
3853:
3769:
3727:
3688:
3610:
3411:
3371:for describing the position of other
3360:
2764:
2519:
2427:
2281:. For example, the orbital period of
2180:
1955:
1949:
1916:
1832:
1795:
1762:
1545:
1535:
1350:
1112:
956:
674:
595:
548:
476:
269:displaying a much higher than normal
192:
16746:
15583:
15507:
15409:Schrijver, C. J.; Zwaan, C. (2008),
15310:MacEvoy, Bruce; Tirion, Wil (2015),
15147:
14816:
14792:
14664:The Astrophysical Journal Supplement
14256:The sequence of positions along the
14174:X-ray bright optically normal galaxy
14107:
14086:A reference to the faintness of the
14005:
13441:
13435:
13289:
13085:(in the case where the primary is a
13064:
13033:
13027:
13000:
12872:
12808:
12768:
12688:, responsible for phenomena such as
12628:
12615:
12256:standard acceleration due to gravity
12134:
12080:
12073:
11969:
11795:
11706:. Faculae occur on other stars (see
11671:
11615:
11567:
11378:
11318:
11124:
10826:
10800:
10762:. Regular moons are thought to form
10745:
10679:
10573:. Quasars emit radiation across the
10503:
10325:, this distance is usually given in
10218:that was explained by the theory of
9952:
9684:
9674:
9586:) is closest to the Earth. Contrast
9253:
9226:
9165:
9116:
9068:
8872:
8531:
8414:that is composed almost entirely of
8231:
8074:
7775:
7727:
7692:
7670:
7393:
7174:
6349:
6097:
5959:
5835:
5615:The vast, bubble-like cavity in the
5326:
5314:
5275:
5154:
4960:
4959:. Larger aggregations may be called
4829:
4801:
4715:
4520:
4416:
4062:
4028:
3800:Of, relating to, or occurring at an
3524:
3304:rather than of all stars in general.
3257:
3227:belonging to a category of ordinary
3123:
3086:point of closest approach to the Sun
2935:to distinguish faint objects in the
2868:
2751:, etc.) across the observer's local
2659:
2652:
2642:origin, evolution, and eventual fate
2405:
2361:
2308:
2246:. The energy from the Sun vaporizes
2023:
1782:
1663:
1256:
1008:
681:
263:A compact region in the center of a
15484:
15412:Solar and Stellar Magnetic Activity
15336:
15257:Introduction to Celestial Mechanics
15150:"Al Khwarizmi: A Medieval Polymath"
15148:Umar, Khalid Bin (18 August 2019),
14299:
14151:
13869:
13856:
13764:The angle between the direction of
13600:
13392:
13156:
13098:
13021:
12702:
12597:
12588:
12432:
12226:
11981:
11933:
11774:
11701:
11608:and because its rotational axis is
11458:
11424:
11355:in the Northern Hemisphere and the
11138:
11045:to radiation at a given depth. See
10780:
10778:, which are thought to be captured.
10773:
10686:
10562:
9989:
9922:
9871:
9817:(but not massive enough to achieve
9776:
9757:
9363:
9343:
9269:
9110:
8996:
8311:, generally by being less than 1.3
8043:
7592:
7428:
7279:
7273:
7255:
7219:in the Northern Hemisphere and the
6840:
6708:
6676:A slight oscillating motion of the
6554:
6255:
6201:
5855:
5697:. Hence, knowing a star's mass and
5367:
5325:. All geosynchronous orbits have a
5308:
5258:
5180:
4953:, each at least as luminous as the
4622:
4153:
3847:
3828:, passes through the center of the
3787:
3586:
3585:of less than 1 (often inclusive of
3556:
3481:
3365:. The ecliptic is widely used as a
3298:
3164:
3106:
3036:
2758:
2269:
2260:
2041:
1974:
1452:
1435:
1391:, and is the cause of the apparent
1329:
1263:
1175:
976:of the visible component. See also
583:
524:
412:is furthest from the Sun. Contrast
341:
240:around a central object, such as a
151:
24:
14631:
13819:
13466:
13247:
12839:
12711:
12067:
11975:
11415:
11361:
11278:
11055:
11047:
10874:into 24 hours, each of 60 minutes.
10850:
10626:
10602:
10521:A moon or planet is said to be in
10266:
9086:
9055:
9026:
8956:A schematic diagram of a complete
8795:
8789:
8664:
7891:
7844:normalized polar moment of inertia
7813:
7706:
7634:
7606:
6961:
6777:
6698:
6530:
6451:
6380:
6365:
6239:
6061:
5928:, forms the dividing line between
5880:
5704:
5680:
5541:
5478:
5400:
5216:or otherwise) with respect to the
5071:
4966:
4923:
4917:
4911:
4865:
4675:
4613:
4586:
4548:
4538:
4432:
4334:
4273:
4255:
4020:, i.e. all objects not covered by
3886:
3859:
3543:
3289:
3228:
3066:
3044:
2999:
2961:
2746:
2471:
2302:
2126:. One measure of this activity is
2029:
1846:
1752:
1719:
1686:The surface velocity at which the
1647:
1429:
965:
736:
179:
173:
25:
17107:
16930:Genetics and evolutionary biology
15890:
15286:Astronomy: A Physical Perspective
15121:
14328:
14080:
14035:
13787:
13606:
13476:
13123:
13092:
12901:. These are typically found at a
12695:
12653:
12401:
12344:
12337:
12167:
12158:
11893:
11783:
11603:
11597:
11572:of the Earth with respect to the
11476:
11430:
11305:
11230:
11194:Rapid variations in the apparent
11168:
11082:
10915:
10744:following a relatively close and
10615:
10433:
10374:
10151:
10145:
10056:
10032:
9905:
9893:
9853:
9828:
9738:from which to measure and define
9734:An arbitrarily chosen, imaginary
9641:
9517:
9384:
9372:
9275:
9219:
9159:
9129:
8842:
8820:
8688:
8624:
8555:
8409:
8376:
8267:
8080:
7993:
7975:
7960:
7954:
7909:
7805:
7790:
7645:
7577:
7547:
7421:The visible passage of a glowing
7368:
7285:
7059:
7047:
6949:
6897:, and is often given in terms of
6889:units, luminosity is measured in
6755:
6659:
6536:
6512:
6457:
6303:
6264:
6169:. This medium mainly consists of
6083:than the Earth and hence, in the
6036:
5992:
5908:of both variable classes overlap.
5740:The approximate region around an
5634:
5320:
5109:
5087:
4973:
4905:
4890:
4721:
4392:
4193:
4147:
4101:
4086:
4043:
3700:
3574:
3453:
3372:
3131:
3078:
3072:
3029:
3017:
2980:
2942:
2924:
2891:
2876:
2811:
2605:
2349:
2121:
2065:
1934:
1218:
1158:
1118:
971:
852:
826:
798:
758:
752:
662:
650:
632:
617:
354:
226:
16745:
16734:
16733:
16504:Southern African Large Telescope
15387:10.1111/j.1365-2966.2008.14227.x
14616:10.1111/j.1365-2966.2004.07627.x
14362:List of common astronomy symbols
14186:that does not appear to have an
13989:
13792:, and also one of six canonical
13734:
13712:
13457:
13434:. This can cause changes in the
13429:
13411:
13298:
13263:
13182:
13132:
13076:
12948:
12802:
12621:
12504:
12395:
12313:
12217:
12114:
11951:
11831:
11721:
11687:
11634:
11625:
11591:
11561:
11515:
11489:
11464:
11449:
11436:
11384:
11311:
11268:
11254:
11240:perihelion precession of Mercury
11177:
11076:
10949:
10943:
10885:
10819:
10439:
10361:embryo that originated within a
10337:
10320:
10294:
10129:
10117:
10020:
9783:
9745:
9610:is closest to the Sun. Contrast
9318:
9306:A planetary system showing a 1:2
9259:
9172:
8352:
8019:
7599:
7570:
7495:
7182:
7118:
7066:
7053:
6995:
6942:The shape of the portion of the
6714:
6450:, which forms a two-dimensional
6438:body relative to another, as an
6137:International Astronomical Union
5948:accompanied by multiple smaller
5929:
5813:
5716:
5698:
5674:
5585:
5484:
5189:
5053:
4847:
4841:
4791:
4743:
4734:
4131:
3637:and an orbiting body, such as a
3275:
3263:
3197:
3113:
2974:
2923:or an object within the Earth's
2829:
2556:
2513:
2439:International Astronomical Union
2418:
2343:
2035:
1989:
1961:
1627:
1609:
1504:
1206:and in other forms of shorthand.
918:
885:
811:
390:
383:
16934:Cellular and molecular biology
15938:, European Southern Observatory
15330:
15313:The Cambridge Double Star Atlas
15248:
15124:"Gcal 4.1: Appendix N Glossary"
14857:The Astronomical Almanac Online
14712:United States Naval Observatory
14700:
14352:List of astronomical catalogues
14198:
13975:
13813:
13776:, as measured from the nearest
13743:
13696:
13534:
13527:
13501:
13481:is low, the result is that the
13316:
13173:
13110:
12924:
12896:
12890:
12857:. The name originated from the
12830:
12796:
12746:
12572:
12362:
12331:
12210:
12141:
11866:
11808:
11678:
11609:
11369:
11096:
11034:
10960:
10730:
10660:
10556:
10523:
10491:
10259:
10092:
9824:cleared its neighbouring region
9753:longitude of the ascending node
9668:
9620:
9483:
9337:
9085:One of two points at which the
9077:
8933:
8863:
8656:
8586:
8400:
8370:
8324:
8128:
8108:
8050:
7761:nor originally classified as a
7735:
7663:
7612:
7482:
7465:A solid piece of debris from a
7446:
7376:One of a set of 110 "nebulous"
7267:
7233:
7133:
7075:
7041:
6821:longitude of the ascending node
6742:
6415:
6392:
6223:
6188:
5942:A system consisting of a large
5923:
5917:
5747:
5650:
5622:
5576:
5490:
5360:
5354:
5339:
5247:geosynchronous equatorial orbit
5229:
5223:
4981:A collective name for the four
4930:
4656:
4580:
4327:, used as a reference point in
4266:, used as a reference point in
4214:or other instrument to take an
4160:
3942:
3498:orbit the Sun with only slight
3423:
3390:
3306:
3204:
3084:
2478:
2355:
2319:
2101:
2034:, i.e. generally inward of the
2017:
1858:
1813:
1621:
1564:
1530:. The barycenter is one of the
1497:
1338:
1272:
936:
867:
679:to describe an orbit. Contrast
670:longitude of the ascending node
414:
320:
270:
247:
219:
185:
175:Harvard spectral classification
146:
15038:Oxford Dictionary of Astronomy
14218:and a companion star are in a
14098:
13923:and their contents, including
13915:1. The entirety of
13812:between the mass or intrinsic
13798:used to characterize an orbit.
13765:
13619:
13590:restricted three-body problems
13520:
13448:
13404:
13386:
13150:
13116:
13040:
13014:in which an object orbits its
12930:
12861:
12729:
12466:
12371:
12120:
11848:
11712:
11534:
11521:
11408:
11249:precession of the Earth's axis
11246:of the Earth–Moon system, and
11161:
11102:
11095:A phenomenon which causes the
10934:
10876:
10635:
10418:of revolution and rotation at
10356:
10347:
10158:
10050:
9935:
9708:
9659:
9527:. It can be determined from a
9463:
9395:
9349:
8908:, such as the trajectory of a
8768:
8749:
8600:
8448:The appearance of the Earth's
8096:
7897:
7699:
7651:
7618:
7586:
7556:
7529:
7510:
7488:
7422:
7261:
6925:
6917:Of or relating to the Earth's
6898:
6857:used to characterize an orbit.
6809:
6790:
6713:in vacuum would travel in one
6517:, extending between 30 and 50
6464:
6117:
6087:
6043:
5965:
5936:
5873:
5842:
5794:, the angular distance on the
5723:
5710:
5607:
5554:
5510:
5394:
5307:about the Earth, i.e. with an
5217:
5167:
5143:
5065:
5059:
5022:
4883:
4876:. Most of the galaxies in the
4807:
4759:
4727:
4643:The region at the center of a
4563:
4526:
4493:
4454:
4386:
4362:
4209:
4200:
4010:
3901:gravitational potential energy
3794:
3755:astronomical coordinate system
3449:astronomical coordinate system
3422:(green), which is permanently
3181:
3170:
3059:extended scattered disc object
2936:
2842:
2796:
2698:
2535:
2470:. It can be observed during a
2394:A phenomenon during which two
2386:
2214:
1875:
1696:
1600:
1587:
1550:where the mass of the central
1503:external to both, as usual in
1444:. Axial tilt is distinct from
1398:
1187:
1181:
896:extreme-environment adaptation
792:
786:
730:
600:used to characterize an orbit.
589:
536:
438:
164:
13:
1:
16014:
15972:International Comet Quarterly
15904:, NASA/IPAC, January 10, 2006
15591:"Components of the Milky Way"
14479:Astrophysical Journal, Part 1
14372:
13677:
13570:
13533:The gradual reduction of the
13329:
13241:
13137:visible in the second body's
12889:One of a class of very large
12689:
12560:
11988:
11957:
11924:
11905:
11730:
11585:
11482:
11160:is a satellite galaxy of the
10476:
10432:A highly magnetized rotating
10190:
10044:
9612:
9596:
9558:
9427:
9266:mean-motion orbital resonance
9207:
8941:
8879:
8825:hypothesized to surround the
8802:
8694:
8296:
8135:
8122:
7717:
7440:
7349:
7164:
7040:. Examples of MACHOs include
6859:
6845:, as measured on a specified
6796:
6625:and is commonly exploited by
6494:
6357:A physical state in which an
6246:
6194:
6022:
5867:
5807:
5780:
5598:
5574:that is the shape of the Sun.
5496:
5160:The point projected upon the
5134:
4948:
4469:The apparent uncommonness of
4461:
4453:. Most flare stars are faint
4423:
4176:
4093:
3965:
3878:
3619:
3469:
3213:
2763:along a circular path on the
2752:
2645:
2621:
2582:
2444:
2299:margin of observational error
2053:
1926:
1852:
1851:around the Sun, known as the
1819:
1638:
1620:orbiting around their common
1512:
1405:
1382:
1360:
1318:
1170:
1050:
986:
846:
542:
368:) compared to adjacent areas.
339:(center) is a prominent dark
141:
15678:Astronomy & Astrophysics
15283:Kutner, Marc Leslie (2003),
15255:Moulton, Forest R. (1970) ,
14909:Astronomy & Astrophysics
13718:
13488:
13465:The net result of continued
13254:
13070:
13015:
12915:
12453:
11552:
11215:
11040:
10891:
10861:equatorial coordinate system
10809:
10767:
10390:
10284:
10183:
10136:
10002:
9839:
9629:
9551:
9533:
9426:. Most of the volume of the
9378:
9371:The hypothetical, idealized
9294:
9197:
8963:
8712:
8646:
8440:
8207:
8200:
8157:An early classification for
8037:
7797:
7625:
7473:
7457:
7343:
7094:
6668:
6506:
6314:
6308:, which are thought to form
6297:
5983:
5800:measured westward along the
5458:gravitational-wave astronomy
5269:
5116:
5078:
4668:
4330:celestial coordinate systems
4269:celestial coordinate systems
4146:in particular, faculae (see
4136:formed by concentrations of
3817:
3801:
3763:
3747:equatorial coordinate system
3645:
3430:
3380:celestial coordinate systems
3077:in the outer reaches of the
2853:equatorial coordinate system
2774:
2715:The apparent movement of an
2640:The scientific study of the
2632:
2612:
2258:radiating away from the Sun.
2112:chromospheric activity index
1969:equatorial coordinate system
1809:equatorial coordinate system
1801:
1423:
1241:
1152:
908:, the possible existence of
530:
468:
431:
7:
15954:HubbleSite – Reference Desk
15932:"ESO Astronomical Glossary"
15920:, Sky & Telescope Media
15732:The Classification of Stars
15708:10.1051/0004-6361/201015809
15564:Husser, Tim-Oliver (2012),
14939:10.1051/0004-6361/201629126
14685:10.1088/0067-0049/187/1/228
14542:10.1051/0004-6361:200810377
14393:Mitton, Jacqueline (2007),
14340:
14304:, the apparent path of the
14259:Hertzsprung–Russell diagram
14181:
14171:
14055:
13936:
13924:
13907:
13893:
13840:
13582:
13560:
13514:
13419:
13344:
13194:
13188:
13144:
13048:
12908:
12848:
12776:
12643:
12544:
12519:
12441:
12419:
12407:
12379:
12352:
12270:and, less importantly, the
12253:
12184:
12040:
12021:
12015:
11887:
11801:
11707:
11652:
11447:as observed from the Earth.
11342:
11326:
11286:
11185:
11147:
10968:
10903:
10816:inertial frame of reference
10721:
10697:Hertzsprung–Russell diagram
10541:
10406:pseudo-synchronous rotation
10368:
10291:inertial frame of reference
10274:
10241:
10227:precession of the equinoxes
10207:precession of the equinoxes
10101:
10078:
10026:
9970:
9960:
9941:
9887:
9881:
9861:
9846:
9725:
9588:
9541:
9531:of the stellar variability.
9455:
9403:
9137:
8947:
8909:
8810:
8672:
8565:
8536:orbits and 180 degrees for
8481:
8389:
8382:
8261:
8239:
8215:
8194:
8151:
8058:
8027:
8009:
7983:
7948:
7928:
7841:
7756:
7755:that is neither a dominant
7639:
7605:A stellar object such as a
7504:
7466:
7408:
7355:
7329:
7314:
7300:mean-motion resonance (MMR)
7206:
7190:
7141:Hertzsprung–Russell diagram
7081:
7014:Massive compact halo object
6981:
6975:
6933:
6874:
6748:
6736:
6641:
6562:
6500:
6472:
6423:
6325:Hertzsprung–Russell diagram
6209:
6164:
5943:
5901:Hertzsprung–Russell diagram
5829:
5773:
5731:
5644:Hertzsprung–Russell diagram
5627:emanating from the Earth's
5519:
5348:
5244:
5210:The position of an object (
5173:
4938:
4899:
4779:
4753:
4703:
4683:
4644:
4630:
4568:
4498:
4470:
4370:
4245:
4169:
4080:
4070:
4055:
4015:
3962:for stars of different mass
3926:Hertzsprung–Russell diagram
3871:
3717:
3643:, as it appears from Earth.
3638:
3564:
3533:
3487:
3332:
3324:
3152:
3052:
3007:
2954:
2948:
2860:. Coordinates north of the
2734:
2706:
2665:
2572:
2566:cosmic microwave background
2543:
2507:
2327:
2188:
2116:A parameter indicating the
2082:
1897:
1669:
1578:
1557:
1479:spherical coordinate system
1413:
1394:precession of the equinoxes
1343:) in the orientation of an
1288:to determine the nature of
1130:
1124:
1090:
1071:
1038:
1016:
944:
875:
763:, i.e. one that orbits the
743:
715:
696:
673:, is used along with other
640:
563:
484:
422:
398:
363:
310:
264:
213:
10:
17112:
17035:Probability and statistics
15792:10.1051/0004-6361:20030163
15762:Astronomy and Astrophysics
15737:Cambridge University Press
15618:Barnes, Rory, ed. (2010),
15464:Ridpath, Ian, ed. (2018),
15439:Astronomy and Astrophysics
15339:Astronomy and Astrophysics
15263:: Dover, pp. 322–23,
15240:Aitken, Robert G. (1935),
14556:Perryman, Michael (2009),
14521:Astronomy and Astrophysics
14357:List of astronomy acronyms
14114:electron-degenerate matter
13701:from the two objects, the
13662:
13576:
13545:due to tidal interactions.
13038:as the primary's rotation.
13032:of the primary and in the
13009:
12966:gravitational acceleration
12528:The outermost region of a
12491:
12425:
12264:gravitational acceleration
12033:
12032:, and the plasma tails of
11911:
11874:The gravitationally bound
11614:to its orbital plane. One
11222:
11200:, color, or position of a
11039:, which describes the net
10617:gravitational perturbation
10544:quasi-stellar radio source
10233:
10167:
10008:
9804:
9635:
9566:
9393:at a given moment in time.
9331:
9235:
9185:
9153:
9092:
9049:
9005:
8983:
8957:
8849:
8706:
8700:
8509:
8302:
8255:
8193:exactly opposite from the
7920:
7762:
7744:
7656:, formed from billions of
7644:that includes the Earth's
7522:
7516:
7434:
7383:
7296:mathematically convenient.
7156:in their core region. The
7127:
6834:
6833:, and the direction of an
6784:
6727:) or 5.88 trillion miles (
6586:
6462:that may exist in reality.
6433:
6409:Kelvin–Helmholtz mechanism
6386:
6212:Laplace's invariable plane
5934:and hydrogen-fusing stars.
5806:from the observer's local
5760:
5537:spectral lines of hydrogen
5524:powered by young, massive
5382:
5376:
5347:Any very large or massive
4709:
4607:galactic coordinate system
3908:
3808:
3708:
3441:ecliptic coordinate system
3139:The apparent motion of an
2991:and have suffered extreme
2917:that is not an individual
2594:consisting of high-energy
2208:clearing the neighbourhood
2200:cis-Neptunian object (CNO)
2059:
2002:
1614:consisting of exactly two
1525:
1461:
973:gravitational perturbation
780:
611:
577:
518:
499:
370:
235:
16805:
16728:
16520:
16497:Large Binocular Telescope
16462:Extremely Large Telescope
16455:Extremely large telescope
16428:
16311:
16251:
16172:
16134:
16095:
16088:
16022:
15815:The Astrophysical Journal
15516:Kepler Mission Star Field
15467:A Dictionary of Astronomy
15096:Westlake, Hannah (2015),
14954:The Astrophysical Journal
14765:A Dictionary of Astronomy
14317:
14278:
14263:
14231:
14147:absolute visual magnitude
14121:
13998:
13930:
13725:
13508:
13494:
13350:
13338:
13303:, approximately 75 to 90
13270:
13207:
13086:
12982:meters per second squared
12936:
12683:
12554:
12529:
12498:
12460:
12424:and other bodies such as
12389:
12308:held together by its own
11901:small Solar System bodies
11841:
11767:
11646:
11261:
11201:
11002:
10789:
10533:
10509:
10424:
10125:small Solar System bodies
10014:
9915:planetary differentiation
9886:-like geology, such as a
9790:
9575:
9494:. The word "parsec" is a
8915:
8711:around the Sun (or other
8633:
8487:
8475:
8331:
8115:electromagnetic radiation
8090:multi-messenger astronomy
8068:
7885:
7657:
7400:
7361:
7087:
6943:
6918:
6868:
6677:
6596:of the large bodies, the
6490:small Solar System bodies
6234:and perpendicular to its
6158:
5662:
4852:, each of which orbits a
4823:
4814:
4579:of 4.100 ± 0.034 million
4398:
4183:
4125:
4116:
4049:
3983:electromagnetic radiation
3930:
3732:and equidistant from its
3520:electromagnetic radiation
3495:small Solar System bodies
3222:
3190:
3158:
2918:
2740:
2728:
2496:A significant release of
2452:
1891:
1727:gravitational contraction
1654:
1615:
1551:
1473:. When combined with the
1366:
1044:
1032:
995:
842:small Solar System bodies
776:small Solar System bodies
724:
702:
689:
553:have exactly two apsides.
455:
446:
291:
280:
241:
201:
16469:Gran Telescopio Canarias
15259:(2nd revised ed.),
15156:, www.tawarikhkhwani.com
14985:10.3847/1538-4357/aafac8
14305:
14287:
14240:
14165:
13690:
13310:
13297:The boundary within the
13200:
13166:
12620:of gases encompassing a
12209:and the measurements of
12129:. This is caused by the
12055:
12049:
12009:
11945:
11939:
11881:
11825:
11789:
11747:
11640:
11584:(e.g. to cross the same
11579:
11573:
11470:
11429:of an object within the
11402:
11396:
10750:orbit with little or no
10575:electromagnetic spectrum
10497:
10455:quadratic field strength
9969:The scientific study of
9605:
9288:
9212:, is commonly used as a
9048:The tilt of an object's
8902:curved trajectory of an
8890:
8826:
8459:
8449:
8423:
8318:
8179:
7903:
7836:moment of inertia factor
7750:
7676:
7323:
7162:is a main-sequence star.
7157:
6955:
6911:
6764:
6690:to be visible along the
6524:
6078:
5628:
5591:
5565:
4785:
4726:about the center of the
4443:electromagnetic spectrum
4404:
4343:
4288:
4141:
4042:that exists outside the
3829:
3673:
3666:
3632:
3459:
3354:
3234:
3146:
2722:
2599:
2501:
2465:
2241:
2232:
2228:electromagnetic spectrum
1983:
1943:
1736:
1372:
1249:The scientific study of
764:
729:recognizable in Earth's
708:
509:
407:
380:chemically peculiar star
277:electromagnetic spectrum
17096:Astronomy-related lists
16830:Artificial intelligence
16564:Astrology and astronomy
16274:Gravitational radiation
15898:"Astronomical Glossary"
15784:2003A&A...401..997P
15700:2011A&A...528A..27H
15649:Sanders, Jason (2015),
15451:1986A&A...165..135R
15351:1981A&A....99..126H
15083:1982A&AS...48..503R
14931:2017A&A...597A..29S
14642:, Infobase Publishing,
14533:2009A&A...493.1099S
14450:Walker, Gordon (1987),
14270:hydrostatic equilibrium
14189:active galactic nucleus
13689:across the face of the
13051:synodic rotation period
12883:supermassive black hole
12723:submillimetre astronomy
12639:stellar evolution model
12547:spectral classification
12292:
12196:observational astronomy
12090:spectral classification
11545:small Solar System body
11154:gravitational potential
11152:that orbits within the
11024:Rosseland optical depth
11001:directly rather than a
10570:supermassive black hole
10552:active galactic nucleus
10472:magnetic field strength
9878:hydrostatic equilibrium
9268:, in which the bodies'
9097:intersects a specified
8737:observational astronomy
8641:stellar classifications
8495:observational astronomy
8292:small Solar System body
8275:small Solar System body
8272:, or sometimes another
8048:and the east direction.
7935:minor natural satellite
7870:
7852:
7388:by French comet hunter
7146:hydrostatic equilibrium
6684:Moon's elliptical orbit
6529:. It is similar to the
6021:), especially chemical
5896:Gamma Doradus variables
5466:observational astronomy
4941:group of galaxies (GrG)
4768:galactocentric distance
4664:active galactic nucleus
4652:supermassive black hole
4576:supermassive black hole
4506:extragalactic astronomy
4409:, as well as all other
4004:extragalactic astronomy
3096:trans-Neptunian objects
3055:distant detached object
2932:observational astronomy
2371:compact stellar nucleus
2157:, after correction for
2096:compact stellar nucleus
2090:supermassive black hole
2013:small Solar System body
1357:Earth's rotational axis
713:, as viewed from Earth.
257:active galactic nucleus
18:Rosseland optical depth
17060:Structural engineering
17000:Mechanical engineering
16973:Western and South Asia
16483:Hubble Space Telescope
14419:Maeder, Andre (2008),
14250:zero-age main sequence
14093:stellar classification
14026:statistical dispersion
13888:UBV photometric system
13835:cosmic distance ladder
13810:empirical relationship
13705:can be used to detect
13655:trans-Neptunian object
13650:
13277:telluric contamination
12821:
12816:planetary-mass objects
12669:stellar magnetic field
12553:The categorization of
12539:stellar classification
12165:
12099:stellar classification
11968:is distinguished from
11605:not perfectly circular
11498:
11212:atmospheric refraction
11158:Large Magellanic Cloud
11031:extinction coefficient
10848:
10531:
10461:stellar magnetic field
10400:pre-main-sequence star
10067:, among other objects.
9961:Also sometimes called
9655:atmospheric resistance
9461:
9316:
9152:takes to complete one
9038:
9031:(yellow) intersects a
8418:, which are a type of
7715:
7002:
6900:astronomical magnitude
6644:Lenakaeia Supercluster
6182:interstellar reddening
5912:hydrogen burning limit
5453:
5410:gravitational collapse
5196:diffusively scattering
4708:takes to complete one
3963:
3617:
3538:with an approximately
3436:
3383:. It differs from the
3377:bodies within various
2994:gravitational collapse
2840:
2837:Hubble Space Telescope
2529:cosmic distance ladder
2366:with very small radii.
2075:central massive object
1994:. It is the basis for
1864:
1592:for the origin of the
1510:
1203:astronomical constants
1066:astronomical catalogue
570:argument of pericenter
352:
275:over some part of the
136:
133:
130:
127:
124:
121:
118:
115:
112:
109:
106:
103:
100:
97:
94:
91:
88:
85:
82:
79:
76:
73:
70:
67:
64:
61:
17086:Glossaries of science
16925:Environmental science
16810:Aerospace engineering
16587:Astroparticle physics
16322:Australian Aboriginal
15626:John Wiley & Sons
15035:Ridpath, Ian (2007),
14853:"Section M: Glossary"
14762:Ridpath, Ian (2012),
14367:Modern constellations
14324:Zodiac constellations
13941:, all other forms of
13900:Johnson–Morgan system
13803:Tully–Fisher relation
13640:
13550:Tisserand's parameter
13400:thick disk population
13371:thick disk population
13360:theoretical astronomy
13230:The component of the
13026:equal to the average
12813:, as well as certain
12154:
11091:rotational modulation
10992:planetary-mass object
10838:
10708:main-sequence turnoff
10520:
10244:gravitational primary
10072:planetary-mass object
10007:objects in or out of
9901:planetary-mass object
9511:partial solar eclipse
9478:shift of exactly one
9445:
9391:orbital state vectors
9305:
9204:Earth's orbital plane
9016:
8763:theoretical astronomy
8433:New General Catalogue
7890:on Earth; because of
7690:
6992:
6636:Laniakea Supercluster
6602:Coriolis acceleration
6475:Edgeworth–Kuiper belt
6278:following a distant,
5658:effective temperature
5440:
5432:gravitational lensing
5287:Artificial satellites
3953:
3837:plane of the ecliptic
3726:perpendicular to its
3684:celestial coordinates
3662:artificial satellites
3607:
3509:effective temperature
3471:plane of the ecliptic
3406:plane of the ecliptic
3401:
3339:plane of the ecliptic
2826:
2490:coronal mass ejection
2404:have either the same
2315:gravitationally bound
2099:, but sometimes both.
2087:, typically either a
2049:cis-Neptunian objects
2028:between those of the
1911:artificial satellites
1830:
1730:and by the fusion of
1494:
1058:astronomical "object"
916:, among other topics.
910:extraterrestrial life
806:distant minor planets
566:argument of perifocus
558:argument of periapsis
487:visual brightness (V)
335:
32:glossary of astronomy
16579:Astronomers Monument
16511:Very Large Telescope
16058:Astronomical symbols
15974:, Harvard University
14708:Astronomical Almanac
14347:Outline of astronomy
14226:
14160:
14075:
13984:
13880:
13676:across a particular
13493:. An example is the
13478:orbital eccentricity
13380:thin disk population
13219:
12990:, which is equal to
12763:artificial satellite
12737:astronomical objects
12497:Of or relating to a
12388:Any small number of
12320:thermonuclear fusion
12300:A massive, luminous
12187:positional astronomy
12108:spectroscopic binary
12008:, released from the
11698:magnetic field lines
11520:. In the context of
11146:A smaller companion
11119:
10928:circumplanetary disk
10759:orbital eccentricity
10643:astronomical objects
10622:Beta Cephei variable
10612:Doppler spectroscopy
10597:
10561:is generated by the
10448:
10311:projected separation
10113:protoplanetary disks
9946:. An example is the
9880:and therefore has a
9845:Of or relating to a
9819:thermonuclear fusion
9583:artificial satellite
9525:cataclysmic variable
9436:
9206:, which defines the
8977:orbital eccentricity
8745:astronomical objects
8595:
8547:nuclear star cluster
8146:
8104:astronomical objects
8067:A loose grouping of
7941:An especially small
7743:An object in direct
7445:through the Earth's
7379:astronomical objects
7138:, in particular the
7006:
6594:gravitational forces
6549:
6401:
6344:
6328:that represents the
6125:astronomical objects
5978:
5661:for a population of
5546:and in star-forming
5505:
5334:geostationary orbits
5295:geosynchronous orbit
5265:geosynchronous orbit
5030:astronomical objects
4775:gravitational center
4479:
4382:astronomical objects
4379:The "background" of
4357:First Point of Aries
4315:The location of the
4310:First Point of Libra
4302:First Point of Libra
4254:The location of the
4239:First Point of Aries
4225:first magnitude star
4188:that lies along the
4182:A randomly situated
4138:magnetic field lines
4111:
4085:outside the Earth's
3656:astronomical objects
3582:orbital eccentricity
3318:orbital eccentricity
3284:
3268:as well as low-mass
2791:
2604:or from outside the
2518:or present during a
2512:, often following a
2397:astronomical objects
2380:nuclear star cluster
2293:common proper motion
2145:is the ratio of the
1887:astronomical objects
1778:reflecting telescope
1747:
1485:
1308:chemical composition
1291:astronomical objects
1148:astronomical objects
1074:astronomical catalog
980:spectroscopic binary
707:with respect to the
605:artificial satellite
463:artificial satellite
159:
16652:List of astronomers
16065:Astronomical object
15837:2004ApJ...612..724Y
15378:2009MNRAS.394.1338B
15227:2005ASPC..335....3S
15188:1981PASP...93..681M
15017:1978IAUS...79...51E
14976:2019ApJ...871..227F
14894:1964SvA.....7..618C
14733:John Wiley and Sons
14676:2010ApJS..187..228S
14607:2004MNRAS.350..189T
14491:1984ApJ...279..763N
14180:A seemingly normal
14135:Wilson–Bappu effect
14112:composed mostly of
14019:velocity dispersion
13964:observable universe
13645:total solar eclipse
13630:total solar eclipse
13563:Tisserand parameter
13324:interstellar medium
13315:, beyond which the
13234:of a star or other
13226:tangential velocity
12788:astronomical object
12742:terahertz radiation
12582:stellar designation
12487:Orion constellation
12179:spherical astronomy
11965:apparent solar time
11752:, or approximately
11566:on Earth, i.e. the
11133:total solar eclipse
10971:interstellar planet
10753:orbital inclination
10706:. It begins at the
10671:astronomical object
10487:ecliptic longitudes
10384:protoplanetary disk
10364:protoplanetary disk
10144:Another name for a
9404:Also simply called
9358:origin of longitude
9149:astronomical object
9043:orbital inclination
8757:observable universe
8728:observable universe
8632:A group of massive
8527:orbital inclination
8342:astronomical object
8119:gravitational waves
8061:stellar association
7248:The fraction of an
7109:astronomical object
6882:astronomical object
6830:origin of longitude
6628:man-made satellites
6147:interstellar medium
6055:orbital inclination
5886:This is a class of
5822:containing Earth's
5743:astronomical object
5618:interstellar medium
5475:gravitational waves
5399:. They differ from
5239:geostationary orbit
5219:center of the Earth
5092:composed mainly of
5016:gamma-ray astronomy
4910:and other types of
4879:observable universe
4784:. For example, the
4750:gravitational field
4699:astronomical object
4514:galactic anticenter
4284:ecliptic coordinate
4232:apparent magnitudes
4124:A bright spot on a
4039:astronomical object
3988:astronomical object
3958:evolutionary tracks
3858:, occur on or near
3696:astronomical object
3551:lenticular galaxies
3142:astronomical object
2969:A star composed of
2914:astronomical object
2835:as detected by the
2785:time of culmination
2718:astronomical object
1997:spherical astronomy
1869:celestial mechanics
1634:optical double star
1595:observable universe
1447:orbital inclination
1313:celestial mechanics
1140:astronomical symbol
1102:observable universe
1085:astronomical object
1028:observable universe
317:diffusely reflected
187:the mass of the Sun
178:system, a class of
48:atmosphere of Earth
16638:Physical cosmology
14295:celestial latitude
14058:Local Supercluster
14049:Virgo Supercluster
14010:or its profile of
13708:extrasolar planets
13651:
13649:as seen from Earth
13422:tidal acceleration
13281:Earth's atmosphere
13069:) relative to the
12658:model of a star's
12614:2. The
12608:stellar atmosphere
12514:stellar atmosphere
12207:spherical geometry
12166:
12029:geomagnetic storms
11919:natural satellites
11244:tidal acceleration
10849:
10674:that emits strong
10532:
10328:astronomical units
10317:angular separation
10220:general relativity
10212:Apsidal precession
9720:plane of reference
9702:photometric system
9491:astronomical units
9462:
9317:
9243:orbital parameters
9215:plane of reference
9124:non-inclined orbit
9100:plane of reference
9063:plane of reference
9039:
8970:frame of reference
8521:plane of reference
8503:non-inclined orbit
8420:subatomic particle
8348:interstellar cloud
7829:molecular hydrogen
7824:interstellar cloud
7716:
7633:1. The
7338:meridian astronomy
7003:
6997:phases of the Moon
6848:plane of reference
6696:of the lunar disk.
6648:Local Supercluster
6484:circumstellar disc
6432:The motion of one
6360:interstellar cloud
6337:evolutionary track
6111:infrared astronomy
5951:satellite galaxies
5906:instability strips
5670:absolute magnitude
5549:irregular galaxies
5454:
5445:gravitational lens
5419:gravitational lens
5206:geometric position
4888:, are much larger.
4573:, consisting of a
4487:galactic astronomy
4217:astronomical image
4023:galactic astronomy
3964:
3918:evolutionary track
3734:geographical poles
3629:angular separation
3618:
3437:
3271:substellar objects
3025:plane of reference
2887:circumstellar disc
2841:
2807:circumstellar disc
2685:circumstellar disc
2413:ecliptic longitude
2191:circumstellar disk
2183:circumstellar disc
1919:celestial meridian
1865:
1848:plane of its orbit
1764:coudé spectrograph
1589:cosmological model
1511:
1235:10 parsecs; 1.5813
1166:phases of the Moon
959:astrometric binary
905:extrasolar planets
859:main asteroid belt
822:circumstellar disc
695:The position of a
658:plane of reference
576:The angle from an
479:apparent magnitude
353:
209:apparent magnitude
195:absolute magnitude
17073:
17072:
17055:Scientific naming
17045:Quantum computing
16875:Computer hardware
16870:Clinical research
16865:Civil engineering
16760:
16759:
16645:Quantum cosmology
16631:Planetary geology
16424:
16423:
16135:Celestial subject
15261:Mineola, New York
14406:978-0-521-82364-7
14239:The point in the
14128:Type Ia supernova
14034:or galaxies in a
13864:nautical twilight
13783:eccentric anomaly
13385:The layer of the
13292:termination shock
13237:astronomical body
13029:rotational period
13003:synchronous orbit
12971:astronomical body
12947:stages or when a
12771:substellar object
12661:stellar evolution
12631:stellar evolution
12559:based upon their
12415:planetary systems
12339:emission spectrum
12272:centrifugal force
11974:. Solar time and
11860:geomagnetic storm
11654:precisely aligned
11611:not perpendicular
11338:celestial equator
11329:southward equinox
11321:September equinox
11010:substellar object
10911:satellite systems
10899:astronomical body
10871:celestial equator
10868:. It divides the
10803:retrograde motion
10741:natural satellite
10648:radio frequencies
10414:, this is a near
10303:retrograde motion
9984:planetary systems
9955:planetary science
9801:astronomical body
9311:orbital resonance
9229:orbital resonance
9193:astronomical body
9146:The time a given
9140:revolution period
9071:orbital mechanics
8929:elliptical orbits
8923:natural satellite
8779:astronomical body
8576:astronomical body
8530:is 0 degrees for
8518:with a specified
8471:celestial objects
8283:near-Earth object
8251:astronomical body
8234:natural satellite
8187:The point on the
8171:giant ellipticals
8012:MK classification
7969:minor-planet moon
7944:natural satellite
7881:natural satellite
7864:natural satellite
7786:natural satellite
7778:minor-planet moon
7308:orbital resonance
7227:September equinox
7202:celestial equator
7193:Northward equinox
7023:astronomical body
6906:visual brightness
6622:trojan satellites
6598:centripetal force
6352:Jeans instability
6275:natural satellite
5958:) as well as its
5863:celestial equator
5803:celestial equator
5316:rotational period
5313:equal to Earth's
5304:synchronous orbit
5156:geocentric zenith
4907:galactic clusters
4796:(approximately 8
4696:The time a given
4439:magnetic activity
4351:celestial equator
4333:. Located in the
4318:September equinox
4296:celestial equator
4272:. Located in the
4065:extrasolar planet
4031:extrasolar object
3783:primary direction
3777:celestial equator
3760:fundamental plane
3739:celestial equator
3527:elliptical galaxy
3477:primary direction
3466:fundamental plane
3386:celestial equator
3239:, in contrast to
3163:) around the two
2971:degenerate matter
2863:celestial equator
2781:lower culmination
2771:upper culmination
2692:break-up velocity
2680:Newtonian gravity
2676:centrifugal force
2668:break-up velocity
2661:critical velocity
2654:critical rotation
2442:in 1930. Compare
2339:astronomical body
2118:magnetic activity
1954:"intersects" the
1880:that studies the
1841:celestial equator
1812:. Due to Earth's
1785:celestial equator
1707:substellar object
1692:Newtonian gravity
1688:centrifugal force
1680:critical rotation
1674:critical velocity
1665:break-up velocity
1362:its orbital plane
1346:astronomical body
1252:celestial objects
1211:astronomical unit
1108:astronomical body
1011:astronomical body
947:planetary geology
930:orbital mechanics
626:natural satellite
550:elliptical orbits
306:astronomical body
44:celestial objects
16:(Redirected from
17103:
16880:Computer science
16787:
16780:
16773:
16764:
16763:
16753:
16749:
16748:
16741:
16737:
16736:
16721:
16712:
16705:
16698:
16691:
16682:
16675:
16668:
16666:Medieval Islamic
16661:
16654:
16647:
16640:
16633:
16626:
16619:
16610:
16603:
16596:
16589:
16582:
16573:
16566:
16559:
16552:
16550:Astroinformatics
16545:
16538:
16531:
16529:Archaeoastronomy
16513:
16506:
16499:
16492:
16490:Keck Observatory
16485:
16478:
16471:
16464:
16457:
16450:
16443:
16417:
16408:
16401:
16394:
16387:
16385:Medieval Islamic
16380:
16373:
16366:
16359:
16352:
16345:
16338:
16331:
16324:
16304:
16297:
16290:
16283:
16276:
16269:
16262:
16244:
16235:
16228:
16221:
16214:
16212:
16204:
16202:
16190:
16183:
16163:
16156:
16149:
16127:
16120:
16113:
16106:
16093:
16092:
16081:
16074:
16067:
16060:
16053:
16044:
16037:
16030:
16009:
16002:
15995:
15986:
15985:
15981:
15980:
15979:
15963:
15962:
15961:
15945:
15944:
15943:
15927:
15926:
15925:
15911:
15910:
15909:
15884:
15883:
15863:
15857:
15856:
15830:
15828:astro-ph/0401117
15810:
15804:
15803:
15777:
15775:astro-ph/0301637
15757:
15751:
15750:
15726:
15720:
15719:
15693:
15673:
15667:
15666:
15646:
15640:
15639:
15615:
15609:
15608:
15607:
15606:
15587:
15581:
15580:
15561:
15555:
15554:
15534:
15528:
15527:
15525:
15524:
15511:
15505:
15504:
15502:
15501:
15488:
15482:
15481:
15461:
15455:
15454:
15445:(1–2): 135–156,
15433:
15427:
15426:
15406:
15400:
15399:
15389:
15372:(3): 1338–1350,
15361:
15355:
15354:
15334:
15328:
15327:
15307:
15301:
15300:
15280:
15274:
15273:
15252:
15246:
15245:
15242:The Binary Stars
15237:
15231:
15230:
15214:
15208:
15207:
15171:
15165:
15164:
15163:
15161:
15145:
15139:
15138:
15137:
15135:
15119:
15113:
15112:
15093:
15087:
15086:
15066:
15060:
15059:
15032:
15021:
15020:
15004:
14998:
14997:
14987:
14969:
14949:
14943:
14942:
14924:
14904:
14898:
14897:
14882:Soviet Astronomy
14877:
14871:
14870:
14869:
14868:
14849:
14814:
14813:
14812:
14811:
14796:
14790:
14789:
14787:
14786:
14759:
14753:
14752:
14750:
14749:
14722:
14716:
14715:
14714:, 2008, Glossary
14704:
14698:
14697:
14687:
14659:
14653:
14652:
14635:
14629:
14628:
14618:
14600:
14598:astro-ph/0312113
14580:
14574:
14573:
14553:
14547:
14546:
14544:
14527:(3): 1099–1107,
14518:
14509:
14503:
14502:
14474:
14468:
14467:
14447:
14441:
14440:
14416:
14410:
14409:
14390:
14320:
14314:
14313:celestial sphere
14308:
14302:
14296:
14290:
14286:The area of the
14266:
14260:
14243:
14190:
14184:
14177:
14154:
14150:of the emitting
14148:
14124:
14110:
14094:
14069:
14038:
14037:galactic cluster
14032:
14031:globular cluster
14008:
14001:
13978:
13965:
13939:
13933:
13927:
13903:
13872:two-body problem
13865:
13859:
13853:
13836:
13826:angular velocity
13822:
13816:
13796:
13795:orbital elements
13790:
13784:
13774:
13773:elliptical orbit
13768:
13759:
13755:
13751:
13721:
13715:
13709:
13699:
13693:
13687:transit of Venus
13680:
13674:
13673:celestial object
13646:
13615:
13609:
13603:
13597:
13596:orbital elements
13591:
13585:
13579:
13573:
13566:
13555:
13543:
13537:
13523:
13517:
13511:
13497:
13491:
13485:
13479:
13473:angular momentum
13469:
13444:
13438:
13437:rotation periods
13432:
13425:
13407:
13401:
13395:
13389:
13353:
13347:
13341:
13325:
13319:
13313:
13307:
13301:
13273:
13250:
13244:
13238:
13203:
13197:
13191:
13185:
13169:
13159:
13153:
13147:
13141:
13140:celestial sphere
13135:
13134:background stars
13119:
13113:
13107:
13101:
13095:
13089:
13079:
13073:
13067:
13061:
13054:
13036:
13030:
13024:
13018:
13012:
12997:
12995:
12988:
12987:standard gravity
12978:
12972:
12951:
12945:
12939:
12933:
12927:
12911:
12905:
12899:
12893:
12875:
12864:
12851:
12817:
12811:
12810:stellar remnants
12805:
12799:
12789:
12782:
12764:
12758:
12738:
12732:
12728:The subfield of
12705:stellar parallax
12698:
12692:
12686:
12662:
12656:
12649:
12624:
12618:
12609:
12600:stellar envelope
12591:stellar dynamics
12575:
12569:
12563:
12557:
12550:
12532:
12525:
12522:stellar envelope
12507:
12501:
12475:
12474:celestial sphere
12469:
12463:
12444:
12435:starburst galaxy
12428:
12422:
12418:, which include
12416:
12410:
12404:
12398:
12392:
12385:
12358:
12340:
12334:
12316:
12289:
12287:
12281:
12279:
12259:
12248:
12239:
12229:standard gravity
12213:
12203:
12202:celestial sphere
12197:
12190:
12161:
12137:
12123:
12117:
12100:
12083:
12076:
12070:
12064:
12058:
12052:
12036:
12030:
12024:
12018:
12012:
11984:
11978:
11972:
11966:
11960:
11954:
11948:
11942:
11936:
11920:
11914:
11908:
11902:
11896:
11890:
11884:
11878:
11877:planetary system
11861:
11844:
11834:
11828:
11804:
11798:
11792:
11786:
11777:solar prominence
11770:
11765:
11760:
11757:
11750:
11704:
11690:
11674:
11668:
11662:
11655:
11649:
11643:
11637:
11621:
11612:
11606:
11600:
11594:
11588:
11582:
11576:
11570:
11564:
11537:
11530:
11529:celestial sphere
11524:
11518:
11510:, including the
11485:
11479:
11473:
11467:
11461:
11445:
11444:celestial sphere
11439:
11433:
11427:
11411:
11405:
11399:
11393:
11392:celestial sphere
11387:
11381:
11364:
11353:autumnal equinox
11345:
11339:
11332:
11314:
11310:, such as for a
11308:
11303:
11292:
11264:
11250:
11218:
11204:
11198:
11191:
11164:
11150:
11141:satellite galaxy
11134:
11113:BY Dra variables
11105:
11099:
11085:
11079:
11073:
11072:background stars
11069:relative to the
11067:
11066:axis of rotation
11050:
11043:
11037:
11017:
11016:planetary system
11011:
11005:
10999:
10993:
10986:
10952:
10946:
10929:
10918:
10912:
10906:
10900:
10894:
10888:
10872:
10862:
10844:
10829:
10822:
10812:
10783:relativistic jet
10776:
10772:, as opposed to
10770:
10760:
10754:
10748:
10742:
10704:
10703:globular cluster
10698:
10689:red-giant branch
10682:
10672:
10656:radio telescopes
10644:
10638:
10634:The subfield of
10618:
10571:
10565:
10559:
10553:
10546:
10526:
10512:
10506:
10500:
10494:
10488:
10465:root mean square
10442:
10436:
10377:
10371:
10365:
10359:
10335:of the observer.
10329:
10323:
10304:
10297:
10287:
10280:
10262:
10255:
10208:
10202:
10201:axis of rotation
10186:
10180:
10170:
10154:
10148:
10132:
10126:
10120:
10114:
10104:
10088:
10065:
10059:
10053:
10047:
10041:
10035:
10029:
10023:
10017:
10011:
10005:
9992:planetary system
9985:
9979:
9973:
9966:
9944:
9938:
9925:planetary nebula
9908:
9902:
9896:
9890:
9884:
9874:
9867:
9864:planetary object
9849:
9831:
9825:
9807:
9802:
9786:
9778:plane of the sky
9772:
9771:equatorial plane
9766:
9765:invariable plane
9760:
9754:
9748:
9742:
9741:orbital elements
9731:
9687:
9686:superior planets
9677:
9676:Inferior planets
9671:
9650:
9649:two-body problem
9644:
9638:
9632:
9615:
9608:
9591:
9584:
9578:
9561:
9554:
9547:
9492:
9488:or 206,265
9486:
9476:
9458:
9451:
9430:
9420:
9419:celestial bodies
9409:
9387:
9381:
9375:
9366:osculating orbit
9352:
9346:
9340:
9334:
9312:
9297:
9291:
9278:
9272:
9262:
9256:
9250:
9244:
9238:
9222:
9216:
9210:
9200:
9194:
9188:
9168:
9162:
9156:
9150:
9143:
9125:
9119:
9113:
9107:
9101:
9095:
9089:
9064:
9058:
9052:
9035:
9029:
9022:
9021:orbital elements
9008:
8999:orbital elements
8992:
8991:elliptical orbit
8986:
8966:
8960:
8953:
8936:
8932:around a common
8930:
8924:
8918:
8912:
8906:
8875:
8845:
8839:inner Oort cloud
8835:
8829:
8823:
8816:
8798:
8792:
8786:
8780:
8764:
8760:, as opposed to
8758:
8752:
8748:with the use of
8746:
8721:
8715:
8709:
8703:
8697:
8691:
8685:
8678:
8659:
8642:
8636:
8616:scientific model
8589:
8583:
8582:axis of rotation
8577:
8540:
8534:
8528:
8524:, such that the
8522:
8512:
8496:
8490:
8484:
8478:
8472:
8462:
8452:
8426:
8412:
8385:
8379:
8373:
8355:
8349:
8343:
8327:
8326:closest approach
8321:
8315:
8305:
8299:
8293:
8276:
8270:
8264:
8258:
8252:
8245:
8225:
8203:
8197:
8191:
8190:celestial sphere
8163:Seyfert galaxies
8131:
8125:
8111:
8105:
8099:
8083:
8077:
8071:
8064:
8046:
8040:
8033:
8015:
7996:
7978:
7970:
7963:
7957:
7951:
7945:
7938:
7912:
7906:
7900:
7894:
7888:
7882:
7865:
7847:
7825:
7808:
7800:
7793:
7787:
7771:
7765:
7759:
7753:
7747:
7730:
7709:
7702:
7701:Milky Way Galaxy
7695:
7679:
7673:
7666:
7660:
7654:
7648:
7642:
7637:
7621:
7615:
7609:
7595:
7589:
7573:
7559:
7525:
7519:
7513:
7507:
7491:
7485:
7469:
7449:
7443:
7437:
7431:
7425:
7418:
7396:
7395:deep-sky objects
7386:
7380:
7364:
7358:
7352:
7346:
7332:
7326:
7309:
7294:
7293:two-body problem
7288:
7282:
7276:
7270:
7264:
7258:
7252:
7251:elliptical orbit
7243:
7228:
7221:autumnal equinox
7209:
7203:
7196:
7177:
7160:
7142:
7136:
7130:
7110:
7090:
7084:
7078:
7062:
7056:
7050:
7044:
7038:
7037:planetary system
7024:
6998:
6984:
6978:
6964:
6963:constantly faces
6958:
6952:
6946:
6939:
6921:
6907:
6901:
6883:
6877:
6871:
6855:
6854:orbital elements
6849:
6843:
6837:
6831:
6805:
6804:elliptical orbit
6799:
6793:
6787:
6767:
6751:
6745:
6739:
6734:
6732:
6726:
6724:
6717:
6711:
6680:
6655:
6629:
6623:
6589:
6583:
6576:
6557:Lagrangian point
6539:
6533:
6527:
6521:
6515:
6509:
6503:
6497:
6491:
6485:
6478:
6460:
6454:
6436:
6429:
6395:
6389:
6383:
6361:
6338:
6332:
6326:
6306:
6300:
6296:orbit about its
6294:
6288:
6282:
6276:
6258:irregular galaxy
6242:
6236:angular momentum
6232:
6231:planetary system
6226:
6219:
6204:invariable plane
6197:
6191:
6167:
6161:
6126:
6120:
6116:The subfield of
6100:
6099:superior planets
6090:
6081:
6056:
6039:
6025:
5995:
5968:
5962:
5952:
5946:
5932:
5926:
5920:
5902:
5876:
5870:
5864:
5858:
5838:
5832:
5826:
5816:
5810:
5804:
5798:
5797:celestial sphere
5792:
5791:celestial object
5776:
5756:
5750:
5744:
5737:
5719:
5713:
5707:
5701:
5695:
5689:
5683:
5677:
5671:
5665:
5659:
5653:
5637:
5631:
5625:
5619:
5594:
5588:
5587:geometric center
5568:
5562:geometric center
5550:
5544:
5522:
5499:
5493:
5487:
5481:
5467:
5446:
5428:
5427:galactic cluster
5403:
5397:
5391:
5385:
5379:
5370:globular cluster
5363:
5357:
5351:
5335:
5329:
5323:
5317:
5311:
5305:
5288:
5282:Earth's rotation
5278:
5272:
5266:
5261:
5254:
5232:
5226:
5220:
5214:
5192:
5183:geometric albedo
5176:
5170:
5164:
5163:celestial sphere
5146:
5145:geometric center
5126:geometric center
5112:
5090:
5074:
5068:
5062:
5056:
5031:
5025:
5021:The subfield of
4985:
4969:
4963:
4957:
4956:Milky Way Galaxy
4951:
4944:
4926:
4920:
4914:
4908:
4902:
4886:
4880:
4874:
4868:
4862:
4856:
4850:
4844:
4838:
4837:interstellar gas
4832:
4831:stellar remnants
4826:
4810:
4804:
4800:) away from the
4794:
4790:is about 27,000
4788:
4782:
4778:of a particular
4776:
4762:
4756:
4746:
4730:
4724:
4718:
4712:
4706:
4700:
4693:
4671:
4665:
4659:
4653:
4647:
4640:
4625:galactic nucleus
4589:
4583:
4577:
4571:
4566:
4560:
4541:
4535:
4534:celestial sphere
4529:
4528:Milky Way Galaxy
4523:
4507:
4501:
4496:
4473:
4457:
4435:
4419:
4418:deep-sky objects
4413:
4407:
4401:
4395:
4389:
4383:
4376:
4373:background stars
4358:
4352:
4346:
4337:
4331:
4325:
4324:celestial sphere
4319:
4303:
4297:
4291:
4285:
4276:
4270:
4264:
4263:celestial sphere
4258:
4251:
4218:
4212:
4196:
4186:
4172:
4156:
4150:
4144:
4134:
4128:
4104:
4089:
4083:
4076:
4058:
4052:
4046:
4040:
4024:
4018:
4013:
3989:
3959:
3945:
3939:
3933:
3929:that a solitary
3927:
3911:
3881:
3874:
3868:
3862:
3856:
3855:autumnal equinox
3850:
3844:
3838:
3832:
3826:
3820:
3804:
3790:
3784:
3778:
3772:
3771:celestial sphere
3766:
3756:
3740:
3730:
3729:axis of rotation
3720:
3703:
3697:
3691:
3690:orbital elements
3685:
3669:
3663:
3657:
3641:
3635:
3613:
3612:elliptical orbit
3595:
3589:
3583:
3577:
3570:
3559:elliptical orbit
3552:
3546:
3536:
3502:
3496:
3490:
3484:
3478:
3472:
3464:or the Earth, a
3462:
3456:
3450:
3433:
3426:
3420:
3414:
3413:celestial sphere
3407:
3393:
3387:
3381:
3375:
3369:
3363:
3362:celestial sphere
3357:
3342:
3319:
3301:
3278:
3272:
3266:
3260:
3259:stellar remnants
3243:
3237:
3231:
3225:
3200:
3193:
3173:
3167:
3161:
3155:
3149:
3143:
3126:
3109:
3103:
3097:
3087:
3081:
3075:
3069:
3062:
3039:
3032:
3026:
3020:
3013:
2995:
2989:
2983:
2977:
2957:
2951:
2945:
2939:
2933:
2927:
2921:
2915:
2894:
2888:
2871:
2864:
2854:
2832:
2814:
2808:
2777:
2767:
2766:celestial sphere
2761:
2755:
2749:
2743:
2737:
2731:
2725:
2719:
2712:
2709:meridian transit
2693:
2686:
2671:
2648:
2624:
2608:
2602:
2578:
2559:
2555:which exists in
2549:
2522:
2521:solar prominence
2516:
2510:
2504:
2474:
2468:
2447:
2440:
2430:
2429:celestial sphere
2426:A region on the
2414:
2408:
2398:
2381:
2364:
2363:stellar remnants
2358:
2352:
2346:
2340:
2333:
2311:
2305:
2272:
2263:commensurability
2244:
2194:
2177:
2147:equivalent width
2144:
2135:
2124:
2097:
2091:
2085:
2068:
2062:
2056:
2050:
2044:
2038:
2032:
2026:
2020:
2014:
1998:
1992:
1991:background stars
1986:
1977:celestial sphere
1970:
1964:
1958:
1957:celestial sphere
1952:
1951:axis of rotation
1946:
1929:
1912:
1906:
1900:
1894:
1888:
1884:of all types of
1878:
1861:
1855:
1849:
1842:
1835:
1834:axis of rotation
1822:
1816:
1810:
1804:
1798:
1797:celestial sphere
1728:
1722:
1708:
1683:
1675:
1650:
1630:
1624:
1618:
1612:
1596:
1590:
1560:
1554:
1548:
1547:planetary system
1538:
1537:elliptical orbit
1528:
1507:
1500:
1455:axis of rotation
1448:
1438:
1432:
1426:
1419:
1401:
1395:
1385:
1379:equatorial bulge
1375:
1369:
1363:
1359:with respect to
1353:
1352:axis of rotation
1347:
1341:
1332:axial precession
1314:
1292:
1266:astrophotography
1259:
1253:
1239:10 light-years).
1238:
1234:
1221:
1204:
1190:
1184:
1178:
1173:
1167:
1161:
1155:
1149:
1133:
1127:
1121:
1115:
1114:planetary system
1109:
1103:
1096:
1093:celestial object
1077:
1059:
1053:
1047:
1041:
1035:
1029:
1022:
1004:
1003:celestial bodies
998:
981:
974:
968:
950:
931:
906:
888:
881:
855:
849:
843:
829:
823:
807:
801:
795:
789:
783:
777:
767:
761:
755:
739:
733:
727:
711:
705:
699:
684:
677:
671:
665:
659:
653:
646:
627:
620:
614:
598:
597:orbital elements
592:
586:
580:
573:
551:
545:
539:
533:
527:
521:
490:
471:
464:
458:
441:
434:
417:
410:
393:
386:
366:
344:
323:
313:
307:
283:
273:
267:
250:
244:
238:
222:
216:
210:
204:
188:
182:
176:
21:
17111:
17110:
17106:
17105:
17104:
17102:
17101:
17100:
17076:
17075:
17074:
17069:
16968:Hebrew toponyms
16963:Arabic toponyms
16801:
16791:
16761:
16756:
16744:
16732:
16724:
16717:
16708:
16701:
16696:X-ray telescope
16694:
16687:
16678:
16671:
16664:
16657:
16650:
16643:
16636:
16629:
16622:
16615:
16606:
16599:
16592:
16585:
16576:
16569:
16562:
16555:
16548:
16541:
16534:
16527:
16516:
16509:
16502:
16495:
16488:
16481:
16474:
16467:
16460:
16453:
16446:
16439:
16431:
16420:
16413:
16404:
16397:
16390:
16383:
16376:
16369:
16362:
16355:
16348:
16341:
16334:
16327:
16320:
16307:
16302:Multi-messenger
16300:
16293:
16286:
16279:
16272:
16265:
16258:
16247:
16240:
16231:
16224:
16217:
16210:
16207:
16198:
16193:
16186:
16179:
16168:
16159:
16152:
16141:
16130:
16125:Space telescope
16123:
16116:
16109:
16102:
16084:
16077:
16070:
16063:
16056:
16049:
16040:
16033:
16026:
16018:
16013:
15977:
15975:
15966:
15959:
15957:
15948:
15941:
15939:
15936:Public Outreach
15930:
15923:
15921:
15917:Astronomy Terms
15914:
15907:
15905:
15896:
15893:
15888:
15887:
15880:
15864:
15860:
15811:
15807:
15768:(3): 997–1007,
15758:
15754:
15747:
15739:, p. 257,
15727:
15723:
15674:
15670:
15663:
15647:
15643:
15636:
15628:, p. 248,
15616:
15612:
15604:
15602:
15589:
15588:
15584:
15578:
15562:
15558:
15551:
15535:
15531:
15522:
15520:
15513:
15512:
15508:
15499:
15497:
15490:
15489:
15485:
15478:
15462:
15458:
15434:
15430:
15423:
15407:
15403:
15362:
15358:
15335:
15331:
15324:
15308:
15304:
15297:
15281:
15277:
15271:
15253:
15249:
15238:
15234:
15215:
15211:
15172:
15168:
15159:
15157:
15146:
15142:
15133:
15131:
15122:Esken, Thomas,
15120:
15116:
15110:
15094:
15090:
15067:
15063:
15049:
15033:
15024:
15005:
15001:
14950:
14946:
14905:
14901:
14878:
14874:
14866:
14864:
14851:
14850:
14817:
14809:
14807:
14798:
14797:
14793:
14784:
14782:
14780:
14772:, p. 163,
14760:
14756:
14747:
14745:
14743:
14735:, p. 110,
14723:
14719:
14706:
14705:
14701:
14660:
14656:
14650:
14636:
14632:
14581:
14577:
14570:
14554:
14550:
14516:
14510:
14506:
14475:
14471:
14464:
14448:
14444:
14437:
14417:
14413:
14407:
14391:
14380:
14375:
14343:
14333:
14283:
14253:
14236:
14229:
14203:
14168:
14163:
14153:late-type stars
14137:
14109:stellar remnant
14103:
14083:
14078:
14052:
14021:
14007:radial velocity
13994:
13987:
13912:
13890:
13883:
13874:
13845:
13805:
13761:
13757:
13753:
13749:
13739:
13730:
13667:
13658:
13632:
13622:
13557:
13553:
13539:of an orbiting
13530:
13504:
13462:
13453:
13416:
13382:
13373:
13362:
13334:
13294:
13266:
13259:
13227:
13222:
13212:
13199:in the Earth's
13178:
13128:
13066:rotation period
13045:
13005:
12993:
12991:
12961:
12958:surface gravity
12920:
12898:mass of the Sun
12886:
12874:inferior planet
12844:
12842:superior planet
12835:
12826:
12773:
12751:
12725:
12716:
12714:stellar remnant
12707:
12671:
12640:
12633:
12617:common envelope
12602:
12593:
12584:
12541:
12516:
12494:
12456:
12437:
12376:
12367:
12349:
12297:
12285:
12283:
12282:(approximately
12277:
12275:
12268:Earth's gravity
12250:
12247:
12241:
12238:
12232:
12222:
12181:
12172:
12146:
12136:radial velocity
12110:
12092:
12082:winter solstice
12075:summer solstice
12045:
12006:alpha particles
11993:
11971:mean solar time
11944:in the Earth's
11929:
11898:, and numerous
11880:of the Earth's
11871:
11853:
11821:
11819:
11816:
11779:
11758:
11755:
11753:
11743:
11741:
11738:
11726:
11717:
11683:
11645:by the Earth's
11630:
11569:rotation period
11557:
11548:
11503:
11494:
11469:in the Earth's
11454:
11420:
11418:sidereal period
11380:rotation period
11374:
11323:
11289:major semi-axis
11283:
11281:semi-major axis
11273:
11257:
11235:
11225:
11182:
11173:
11143:
11127:
11122:
11092:
11060:
11058:rotation period
11026:
10998:galactic center
10983:starless planet
10965:
10939:
10922:Rings of Saturn
10896:that orbits an
10881:
10855:
10853:right ascension
10828:prograde motion
10805:
10794:
10785:
10775:irregular moons
10735:
10726:
10691:
10681:radio astronomy
10665:
10631:
10629:radio astronomy
10607:
10605:radial velocity
10600:
10538:
10505:superior planet
10481:
10467:of a series of
10456:
10451:
10429:
10416:synchronization
10412:eccentric orbit
10407:
10395:
10386:
10352:
10342:
10312:
10271:
10269:prograde motion
10238:
10229:
10195:
10163:
10141:
10097:
10075:
9999:gravitationally
9994:
9957:
9932:emission nebula
9927:
9917:
9858:
9842:
9795:
9779:
9728:reference plane
9722:
9713:
9704:
9664:
9625:
9601:
9571:
9538:
9520:
9513:
9469:
9439:
9424:minimal gravity
9400:
9368:
9359:
9323:
9307:
9271:orbital periods
9255:semi-major axis
9231:
9184:defined by the
9182:geometric plane
9177:
9167:sidereal period
9134:
9118:descending node
9103:to which it is
9082:
9073:
9045:
9034:reference plane
9001:
8979:
8944:
8900:gravitationally
8895:
8884:
8874:molecular cloud
8868:
8854:
8813:Öpik–Oort cloud
8807:
8773:
8739:
8730:
8669:
8667:observation arc
8651:
8629:
8603:
8598:
8570:
8560:
8550:
8505:
8445:
8436:
8405:
8394:
8336:
8286:
8236:
8212:
8184:
8159:active galaxies
8154:
8149:
8140:
8092:
8076:molecular cloud
8055:
8024:
8006:
7988:
7925:
7875:
7857:
7838:
7818:
7816:molecular cloud
7780:
7740:
7729:semi-minor axis
7722:
7672:Galactic Center
7630:
7602:
7582:
7552:
7534:
7500:
7478:
7462:
7405:
7390:Charles Messier
7373:
7339:
7319:
7301:
7245:
7239:
7187:
7176:semi-major axis
7169:
7148:and undergoing
7123:
7099:
7071:
7017:
7009:
6930:
6914:
6864:
6824:
6814:
6780:
6779:line of apsides
6760:
6730:
6728:
6722:
6720:
6704:
6673:
6664:
6638:
6617:
6610:
6569:libration point
6559:
6552:
6469:
6426:Keplerian orbit
6420:
6411:
6404:
6371:
6354:
6347:
6322:A curve on the
6319:
6269:
6260:
6251:
6206:
6184:
6150:
6140:
6113:
6066:
6064:inferior planet
6048:
5988:
5981:
5961:galactic corona
5939:
5925:mass of the Sun
5913:
5888:pulsating stars
5883:
5882:hybrid pulsator
5866:. Similar to a
5857:celestial poles
5847:
5837:right ascension
5825:rotational axis
5785:
5765:
5728:
5646:
5612:
5603:
5590:of the Earth's
5581:
5564:of the Earth's
5557:
5543:spiral galaxies
5515:
5508:
5460:
5421:
5412:
5372:
5344:
5328:semi-major axis
5298:
5241:
5207:
5185:
5157:
5139:
5130:oblate spheroid
5121:
5083:
5045:
5042:gamma-ray burst
5018:
4993:Galileo Galilei
4978:
4962:galaxy clusters
4935:
4895:
4819:
4803:Galactic Center
4769:
4739:
4717:galactic center
4680:
4678:galactic period
4637:galactic center
4627:
4618:
4616:galactic corona
4609:
4556:The rotational
4553:
4551:Galactic Center
4516:
4489:
4482:
4466:
4428:
4403:other than the
4367:
4312:
4242:
4227:
4205:
4179:
4165:
4121:
4114:
4096:
4067:
4033:
4006:
3970:
3923:A curve on the
3920:
3891:
3889:escape velocity
3813:
3797:
3749:
3713:
3678:
3650:
3624:
3588:circular orbits
3561:
3529:
3511:
3443:
3389:because of the
3368:reference plane
3349:defined by the
3329:
3311:
3300:late-type stars
3294:
3292:early-type star
3287:
3233:stars like the
3218:
3209:
3186:
3169:in the Earth's
3166:celestial poles
3157:, or a distant
3136:
3125:prograde motion
3118:
3049:
3047:detached object
3004:
3002:descending node
2966:
2964:degenerate star
2908:
2905:deep-sky object
2893:Keplerian orbit
2881:
2870:right ascension
2847:
2818:infrared excess
2801:
2794:
2703:
2662:
2655:
2637:
2617:
2587:
2569:
2540:
2531:
2493:
2483:
2457:
2423:
2407:right ascension
2391:
2373:
2324:
2310:radial velocity
2294:
2271:orbital periods
2265:
2237:
2219:
2210:
2201:
2185:
2175:
2169:
2142:
2137:
2133:
2127:
2113:
2106:
2078:
2046:. Centaurs are
2043:Jupiter trojans
2040:but beyond the
2025:semi-major axis
2007:
1979:
1939:
1921:
1914:, among others.
1871:
1787:
1765:
1757:
1755:Calibrator star
1750:
1741:
1701:
1666:
1659:
1643:
1605:
1586:The prevailing
1583:
1569:
1517:
1488:
1466:
1457:
1410:
1377:on the Earth's
1334:
1323:
1277:
1268:
1246:
1236:
1232:
1214:
1142:
1087:
1068:
1013:
991:
961:
941:
923:
872:
816:
748:
723:Any pattern of
720:
692:
683:descending node
637:
607:
560:
514:
504:
481:
451:
427:
403:
375:
359:
303:received by an
301:solar radiation
296:
260:
231:
218:, or 32.6
200:A measure of a
197:
169:
162:
157:
156:
57:
28:
23:
22:
15:
12:
11:
5:
17109:
17099:
17098:
17093:
17088:
17071:
17070:
17068:
17067:
17062:
17057:
17052:
17047:
17042:
17037:
17032:
17027:
17022:
17020:Nanotechnology
17017:
17012:
17007:
17002:
16997:
16992:
16990:Machine vision
16987:
16982:
16977:
16976:
16975:
16970:
16965:
16960:
16955:
16947:
16946:
16945:
16940:
16932:
16927:
16922:
16917:
16916:
16915:
16910:
16902:
16897:
16892:
16887:
16882:
16877:
16872:
16867:
16862:
16857:
16852:
16847:
16842:
16837:
16832:
16827:
16822:
16817:
16812:
16806:
16803:
16802:
16793:Glossaries of
16790:
16789:
16782:
16775:
16767:
16758:
16757:
16755:
16754:
16742:
16729:
16726:
16725:
16723:
16722:
16715:
16714:
16713:
16706:
16699:
16685:
16684:
16683:
16676:
16669:
16662:
16648:
16641:
16634:
16627:
16620:
16613:
16612:
16611:
16597:
16590:
16583:
16574:
16567:
16560:
16553:
16546:
16543:Astrochemistry
16539:
16532:
16524:
16522:
16518:
16517:
16515:
16514:
16507:
16500:
16493:
16486:
16479:
16476:Hale Telescope
16472:
16465:
16458:
16451:
16444:
16436:
16434:
16426:
16425:
16422:
16421:
16419:
16418:
16411:
16410:
16409:
16395:
16388:
16381:
16374:
16367:
16360:
16353:
16346:
16339:
16332:
16325:
16317:
16315:
16309:
16308:
16306:
16305:
16298:
16291:
16284:
16277:
16270:
16263:
16255:
16253:
16249:
16248:
16246:
16245:
16238:
16237:
16236:
16222:
16215:
16209:Visible-light
16205:
16191:
16184:
16176:
16174:
16170:
16169:
16167:
16166:
16165:
16164:
16150:
16138:
16136:
16132:
16131:
16129:
16128:
16121:
16114:
16107:
16099:
16097:
16090:
16086:
16085:
16083:
16082:
16075:
16068:
16061:
16054:
16047:
16046:
16045:
16031:
16023:
16020:
16019:
16012:
16011:
16004:
15997:
15989:
15983:
15982:
15964:
15946:
15928:
15912:
15892:
15891:External links
15889:
15886:
15885:
15878:
15858:
15845:10.1086/422802
15821:(2): 724–728,
15805:
15752:
15745:
15721:
15668:
15662:978-3319187723
15661:
15641:
15635:978-3527408962
15634:
15610:
15582:
15577:978-3863950927
15576:
15556:
15549:
15529:
15506:
15483:
15477:978-0192542618
15476:
15456:
15428:
15422:978-1139425421
15421:
15401:
15356:
15329:
15323:978-1107534209
15322:
15302:
15295:
15275:
15269:
15247:
15232:
15209:
15196:10.1086/130908
15166:
15154:TAWARIKHKHWANI
15140:
15114:
15109:978-1785461477
15108:
15088:
15061:
15047:
15022:
14999:
14944:
14899:
14872:
14815:
14804:Universe Today
14791:
14779:978-0199609055
14778:
14754:
14741:
14717:
14699:
14670:(1): 228–250,
14654:
14649:978-1438109329
14648:
14630:
14591:(1): 189–195,
14575:
14569:978-0521514897
14568:
14548:
14504:
14499:10.1086/161945
14469:
14462:
14442:
14436:978-3540769491
14435:
14411:
14405:
14377:
14376:
14374:
14371:
14370:
14369:
14364:
14359:
14354:
14349:
14342:
14339:
14338:
14337:
14334:
14331:zodiacal light
14329:
14327:
14284:
14279:
14277:
14274:nuclear fusion
14254:
14248:
14246:
14237:
14232:
14228:
14225:
14224:
14223:
14204:
14199:
14197:
14194:X-ray emission
14172:An acronym of
14169:
14166:
14162:
14159:
14158:
14157:
14138:
14133:
14131:
14118:nuclear fusion
14104:
14099:
14097:
14088:spectral lines
14084:
14082:weak-line star
14081:
14077:
14074:
14073:
14072:
14053:
14047:
14045:
14042:virial theorem
14022:
14017:
14015:
14012:spectral lines
13995:
13990:
13986:
13983:
13982:
13981:
13968:
13913:
13908:
13906:
13896:Johnson system
13891:
13886:
13882:
13879:
13878:
13877:
13875:
13870:
13868:
13846:
13841:
13839:
13806:
13801:
13799:
13762:
13744:
13742:
13740:
13735:
13733:
13731:
13726:
13724:
13703:transit method
13683:
13668:
13663:
13661:
13659:
13653:
13635:
13633:
13628:
13626:
13623:
13620:
13618:
13602:semimajor axis
13558:
13548:
13546:
13531:
13528:
13526:
13505:
13502:
13500:
13463:
13458:
13456:
13454:
13449:
13447:
13417:
13412:
13410:
13394:galactic plane
13383:
13378:
13376:
13374:
13369:
13367:
13363:
13358:
13356:
13335:
13330:
13328:
13295:
13290:
13288:
13267:
13264:
13262:
13260:
13255:
13253:
13228:
13225:
13221:
13218:
13217:
13216:
13213:
13208:
13206:
13179:
13174:
13172:
13158:orbital period
13129:
13126:synodic period
13124:
13122:
13100:orbital period
13046:
13041:
13039:
13035:same direction
13023:orbital period
13006:
13001:
12999:
12962:
12956:
12954:
12921:
12916:
12914:
12887:
12881:
12879:
12845:
12840:
12838:
12836:
12831:
12829:
12827:
12822:
12820:
12774:
12769:
12767:
12752:
12747:
12745:
12726:
12721:
12719:
12717:
12712:
12710:
12708:
12703:
12701:
12676:magnetic field
12672:
12667:
12665:
12641:
12638:
12636:
12634:
12629:
12627:
12612:
12603:
12598:
12596:
12594:
12589:
12587:
12585:
12580:
12578:
12542:
12537:
12535:
12517:
12512:
12510:
12495:
12492:
12490:
12457:
12454:
12452:
12438:
12433:
12431:
12382:stellar system
12377:
12372:
12370:
12368:
12363:
12361:
12350:
12347:star catalogue
12345:
12343:
12298:
12293:
12291:
12251:
12245:
12236:
12227:
12225:
12223:
12218:
12216:
12182:
12177:
12175:
12173:
12170:speed of light
12168:
12149:
12147:
12142:
12140:
12131:Doppler effect
12111:
12106:
12104:
12093:
12088:
12086:
12046:
12041:
12039:
11994:
11989:
11987:
11983:ephemeris time
11935:diurnal motion
11930:
11925:
11923:
11872:
11867:
11865:
11854:
11849:
11847:
11822:
11817:
11814:
11809:
11807:
11780:
11775:
11773:
11744:
11739:
11736:
11731:
11729:
11727:
11722:
11720:
11718:
11713:
11711:
11694:solar granules
11684:
11679:
11677:
11631:
11626:
11624:
11558:
11553:
11551:
11549:
11543:
11541:
11504:
11499:
11497:
11495:
11490:
11488:
11460:diurnal motion
11455:
11450:
11448:
11426:orbital period
11421:
11416:
11414:
11375:
11370:
11368:
11357:vernal equinox
11324:
11319:
11317:
11284:
11279:
11277:
11274:
11269:
11267:
11258:
11255:
11253:
11236:
11233:secular motion
11231:
11229:
11226:
11223:
11221:
11183:
11178:
11176:
11174:
11171:scattered disc
11169:
11167:
11144:
11139:
11137:
11128:
11125:
11121:
11118:
11117:
11116:
11093:
11090:
11088:
11061:
11056:
11054:
11027:
11022:
11020:
10995:that orbits a
10966:
10961:
10959:
10940:
10935:
10933:
10920:, as with the
10882:
10877:
10875:
10856:
10851:
10833:
10806:
10801:
10799:
10795:
10790:
10788:
10786:
10781:
10779:
10736:
10731:
10729:
10727:
10722:
10720:
10700:for a typical
10692:
10687:
10685:
10666:
10661:
10659:
10652:radio antennas
10650:, using large
10632:
10627:
10625:
10608:
10603:
10599:
10596:
10595:
10594:
10591:emission lines
10567:of gas onto a
10539:
10534:
10515:
10482:
10477:
10475:
10457:
10454:
10450:
10447:
10446:
10445:
10430:
10425:
10423:
10408:
10405:
10403:
10396:
10391:
10389:
10387:
10382:
10380:
10353:
10348:
10346:
10343:
10338:
10336:
10313:
10310:
10308:
10272:
10267:
10265:
10239:
10234:
10232:
10230:
10225:
10223:
10196:
10191:
10189:
10164:
10159:
10157:
10142:
10137:
10135:
10098:
10093:
10091:
10085:planetary body
10076:
10070:
10068:
9995:
9990:
9988:
9958:
9953:
9951:
9928:
9923:
9921:
9918:
9913:
9911:
9873:secondary body
9859:
9856:planetary body
9854:
9852:
9843:
9840:
9838:
9796:
9791:
9789:
9780:
9777:
9775:
9759:ecliptic plane
9723:
9718:
9716:
9714:
9709:
9707:
9705:
9700:
9698:
9665:
9660:
9658:
9626:
9621:
9619:
9602:
9597:
9595:
9572:
9567:
9565:
9539:
9534:
9532:
9521:
9519:peak magnitude
9518:
9516:
9514:
9509:
9507:
9470:
9464:
9438:
9435:
9434:
9433:
9401:
9396:
9394:
9369:
9364:
9362:
9360:
9357:
9355:
9345:orbital period
9324:
9319:
9300:
9232:
9227:
9225:
9180:The imaginary
9178:
9173:
9171:
9135:
9132:orbital period
9130:
9128:
9112:ascending node
9083:
9078:
9076:
9074:
9069:
9067:
9046:
9041:
9011:
9002:
8997:
8995:
8980:
8975:
8973:
8945:
8942:
8940:
8935:center of mass
8896:
8891:
8889:
8885:
8880:
8878:
8869:
8864:
8862:
8855:
8850:
8848:
8808:
8803:
8801:
8774:
8769:
8767:
8740:
8735:
8733:
8731:
8726:
8724:
8670:
8665:
8663:
8652:
8647:
8645:
8630:
8627:OB association
8625:
8623:
8604:
8601:
8597:
8594:
8593:
8592:
8571:
8566:
8564:
8561:
8558:number density
8556:
8554:
8551:
8545:
8543:
8506:
8501:
8499:
8446:
8441:
8439:
8437:
8431:
8429:
8406:
8401:
8399:
8395:
8390:
8388:
8337:
8332:
8330:
8287:
8281:
8279:
8237:
8232:
8230:
8213:
8208:
8206:
8185:
8180:
8178:
8175:emission lines
8155:
8152:
8148:
8145:
8144:
8143:
8141:
8136:
8134:
8093:
8088:
8086:
8056:
8051:
8049:
8045:celestial body
8025:
8020:
8018:
8007:
8002:
8000:
7989:
7984:
7982:
7926:
7921:
7919:
7876:
7871:
7869:
7858:
7853:
7851:
7839:
7834:
7832:
7819:
7814:
7812:
7789:that orbits a
7781:
7776:
7774:
7741:
7736:
7734:
7723:
7718:
7685:
7682:
7631:
7626:
7624:
7603:
7600:
7598:
7594:micrometeorite
7583:
7580:micrometeoroid
7578:
7576:
7553:
7550:micrometeorite
7548:
7546:
7535:
7530:
7528:
7501:
7496:
7494:
7479:
7474:
7472:
7463:
7458:
7456:
7430:micrometeoroid
7406:
7401:
7399:
7374:
7371:Messier object
7369:
7367:
7340:
7337:
7335:
7320:
7315:
7313:
7302:
7299:
7297:
7281:orbital period
7275:circular orbit
7246:
7234:
7232:
7217:vernal equinox
7188:
7183:
7181:
7170:
7165:
7163:
7150:nuclear fusion
7126:A category of
7124:
7119:
7117:
7100:
7095:
7093:
7072:
7067:
7065:
7018:
7012:
7008:
7005:
7004:
6987:
6931:
6926:
6924:
6915:
6912:
6910:
6893:per second or
6865:
6860:
6858:
6842:ascending node
6825:
6819:
6817:
6815:
6810:
6808:
6781:
6778:
6776:
6761:
6758:limb darkening
6756:
6754:
6710:speed of light
6705:
6699:
6697:
6674:
6669:
6667:
6665:
6662:late-type star
6660:
6658:
6639:
6634:
6632:
6615:
6608:
6565:Lagrange point
6560:
6555:
6551:
6548:
6547:
6546:
6470:
6465:
6463:
6421:
6416:
6414:
6412:
6407:
6403:
6400:
6399:
6398:
6372:
6366:
6364:
6355:
6350:
6346:
6343:
6342:
6341:
6320:
6315:
6313:
6270:
6267:irregular moon
6265:
6263:
6261:
6256:
6254:
6252:
6247:
6245:
6207:
6202:
6200:
6185:
6180:
6178:
6151:
6145:
6143:
6141:
6135:
6133:
6128:detectable at
6114:
6109:
6107:
6067:
6062:
6060:
6049:
6044:
6042:
5989:
5984:
5980:
5977:
5976:
5975:
5940:
5937:
5935:
5914:
5911:
5909:
5884:
5881:
5879:
5850:Any imaginary
5848:
5843:
5841:
5786:
5781:
5779:
5766:
5761:
5759:
5729:
5724:
5722:
5647:
5642:
5640:
5613:
5608:
5606:
5604:
5599:
5597:
5582:
5577:
5575:
5558:
5555:
5553:
5516:
5511:
5507:
5504:
5503:
5502:
5461:
5456:
5435:
5422:
5417:
5415:
5413:
5408:
5406:
5373:
5368:
5366:
5345:
5340:
5338:
5310:orbital period
5299:
5293:
5291:
5277:same direction
5242:
5237:
5235:
5208:
5205:
5203:
5186:
5181:
5179:
5158:
5155:
5153:
5140:
5135:
5133:
5122:
5117:
5115:
5084:
5079:
5077:
5046:
5040:
5038:
5033:detectable at
5019:
5014:
5012:
4991:discovered by
4979:
4976:Galilean moons
4974:
4972:
4936:
4931:
4929:
4896:
4893:galaxy cluster
4891:
4889:
4855:center of mass
4820:
4815:
4813:
4770:
4767:
4765:
4740:
4735:
4733:
4681:
4676:
4674:
4628:
4623:
4621:
4619:
4614:
4612:
4610:
4605:
4603:
4588:constellations
4554:
4549:
4547:
4517:
4512:
4510:
4490:
4485:
4481:
4478:
4477:
4476:
4467:
4462:
4460:
4429:
4424:
4422:
4368:
4363:
4361:
4313:
4308:
4306:
4243:
4237:
4235:
4228:
4223:
4221:
4206:
4201:
4199:
4180:
4177:
4175:
4166:
4161:
4159:
4122:
4117:
4113:
4110:
4109:
4108:
4097:
4094:
4092:
4068:
4063:
4061:
4034:
4029:
4027:
4007:
4002:
4000:
3971:
3966:
3948:
3921:
3916:
3914:
3913:of any radius.
3905:center of mass
3897:kinetic energy
3892:
3887:
3885:
3873:directly above
3849:vernal equinox
3814:
3809:
3807:
3798:
3795:
3793:
3789:vernal equinox
3750:
3745:
3743:
3714:
3709:
3707:
3679:
3674:
3672:
3651:
3646:
3644:
3625:
3620:
3602:
3567:elliptic orbit
3562:
3557:
3555:
3530:
3525:
3523:
3512:
3507:
3505:
3483:vernal equinox
3444:
3439:
3396:
3335:ecliptic plane
3330:
3325:
3323:
3312:
3307:
3305:
3295:
3290:
3286:
3283:
3282:
3281:
3219:
3214:
3212:
3210:
3205:
3203:
3187:
3182:
3180:
3177:diurnal circle
3137:
3134:diurnal motion
3132:
3130:
3119:
3114:
3112:
3108:scattered disc
3050:
3045:
3043:
3038:ascending node
3005:
3000:
2998:
2967:
2962:
2960:
2909:
2903:
2901:
2882:
2879:decretion disk
2877:
2875:
2848:
2843:
2827:Circumstellar
2821:
2804:A ring-shaped
2802:
2797:
2793:
2790:
2789:
2788:
2760:appear to move
2704:
2699:
2697:
2663:
2660:
2658:
2656:
2653:
2651:
2638:
2633:
2631:
2618:
2613:
2611:
2588:
2583:
2581:
2570:
2564:
2562:
2541:
2536:
2534:
2532:
2527:
2525:
2494:
2488:
2486:
2484:
2479:
2477:
2458:
2453:
2451:
2424:
2419:
2417:
2392:
2387:
2385:
2374:
2369:
2367:
2330:compact object
2325:
2320:
2318:
2295:
2292:
2290:
2266:
2261:
2259:
2238:
2233:
2231:
2220:
2215:
2213:
2211:
2206:
2204:
2202:
2199:
2197:
2186:
2181:
2179:
2173:
2161:light, to the
2151:singly ionized
2140:
2131:
2114:
2111:
2109:
2107:
2102:
2100:
2079:
2073:
2071:
2016:with either a
2008:
2003:
2001:
1980:
1975:
1973:
1940:
1937:celestial pole
1935:
1933:
1922:
1917:
1915:
1874:The branch of
1872:
1867:
1825:
1790:The imaginary
1788:
1783:
1781:
1772:placed at the
1766:
1763:
1761:
1758:
1753:
1749:
1746:
1745:
1744:
1742:
1737:
1735:
1712:nuclear fusion
1702:
1697:
1695:
1667:
1664:
1662:
1660:
1655:
1653:
1644:
1639:
1637:
1606:
1601:
1599:
1584:
1579:
1577:
1570:
1565:
1563:
1522:center of mass
1518:
1513:
1487:
1484:
1483:
1482:
1467:
1462:
1460:
1458:
1453:
1451:
1437:orbital period
1411:
1406:
1404:
1335:
1330:
1328:
1324:
1319:
1317:
1278:
1273:
1271:
1269:
1264:
1262:
1247:
1242:
1240:
1225:semimajor axis
1215:
1209:
1207:
1177:constellations
1143:
1138:
1136:
1088:
1083:
1081:
1069:
1064:
1062:
1019:celestial body
1014:
1009:
1007:
992:
987:
985:
962:
957:
955:
942:
937:
935:
924:
919:
917:
898:on Earth, the
873:
868:
866:
817:
812:
810:
749:
744:
742:
721:
716:
714:
693:
690:
688:
638:
635:ascending node
633:
631:
608:
603:
601:
585:ascending node
561:
556:
554:
526:planetary body
515:
510:
508:
505:
500:
498:
482:
477:
475:
452:
447:
445:
428:
423:
421:
404:
399:
397:
376:
371:
369:
360:
357:albedo feature
355:
343:albedo feature
330:
297:
292:
290:
261:
255:
253:
232:
229:accretion disk
227:
225:
198:
193:
191:
170:
165:
161:
158:
155:
154:
152:External links
149:
144:
139:
58:
56:
53:
26:
9:
6:
4:
3:
2:
17108:
17097:
17094:
17092:
17089:
17087:
17084:
17083:
17081:
17066:
17063:
17061:
17058:
17056:
17053:
17051:
17048:
17046:
17043:
17041:
17038:
17036:
17033:
17031:
17028:
17026:
17023:
17021:
17018:
17016:
17013:
17011:
17008:
17006:
17003:
17001:
16998:
16996:
16993:
16991:
16988:
16986:
16983:
16981:
16978:
16974:
16971:
16969:
16966:
16964:
16961:
16959:
16956:
16954:
16951:
16950:
16948:
16944:
16941:
16939:
16936:
16935:
16933:
16931:
16928:
16926:
16923:
16921:
16918:
16914:
16911:
16909:
16906:
16905:
16903:
16901:
16898:
16896:
16893:
16891:
16888:
16886:
16883:
16881:
16878:
16876:
16873:
16871:
16868:
16866:
16863:
16861:
16858:
16856:
16853:
16851:
16848:
16846:
16843:
16841:
16838:
16836:
16833:
16831:
16828:
16826:
16823:
16821:
16818:
16816:
16813:
16811:
16808:
16807:
16804:
16800:
16796:
16788:
16783:
16781:
16776:
16774:
16769:
16768:
16765:
16752:
16743:
16740:
16731:
16730:
16727:
16720:
16716:
16711:
16707:
16704:
16700:
16697:
16693:
16692:
16690:
16686:
16681:
16677:
16674:
16670:
16667:
16663:
16660:
16656:
16655:
16653:
16649:
16646:
16642:
16639:
16635:
16632:
16628:
16625:
16621:
16618:
16614:
16609:
16605:
16604:
16602:
16601:Constellation
16598:
16595:
16591:
16588:
16584:
16581:
16580:
16575:
16572:
16568:
16565:
16561:
16558:
16554:
16551:
16547:
16544:
16540:
16537:
16533:
16530:
16526:
16525:
16523:
16519:
16512:
16508:
16505:
16501:
16498:
16494:
16491:
16487:
16484:
16480:
16477:
16473:
16470:
16466:
16463:
16459:
16456:
16452:
16449:
16445:
16442:
16438:
16437:
16435:
16433:
16427:
16416:
16412:
16407:
16403:
16402:
16400:
16396:
16393:
16389:
16386:
16382:
16379:
16375:
16372:
16368:
16365:
16361:
16358:
16354:
16351:
16347:
16344:
16340:
16337:
16333:
16330:
16326:
16323:
16319:
16318:
16316:
16314:
16310:
16303:
16299:
16296:
16292:
16289:
16285:
16282:
16278:
16275:
16271:
16268:
16264:
16261:
16257:
16256:
16254:
16252:Other methods
16250:
16243:
16239:
16234:
16230:
16229:
16227:
16223:
16220:
16216:
16213:
16206:
16201:
16196:
16192:
16189:
16188:Submillimetre
16185:
16182:
16178:
16177:
16175:
16171:
16162:
16158:
16157:
16155:
16151:
16148:
16147:Extragalactic
16144:
16140:
16139:
16137:
16133:
16126:
16122:
16119:
16115:
16112:
16111:Observational
16108:
16105:
16101:
16100:
16098:
16094:
16091:
16087:
16080:
16076:
16073:
16069:
16066:
16062:
16059:
16055:
16052:
16048:
16043:
16039:
16038:
16036:
16032:
16029:
16025:
16024:
16021:
16017:
16010:
16005:
16003:
15998:
15996:
15991:
15990:
15987:
15973:
15969:
15965:
15955:
15951:
15947:
15937:
15933:
15929:
15919:
15918:
15913:
15903:
15899:
15895:
15894:
15881:
15875:
15871:
15870:
15862:
15854:
15850:
15846:
15842:
15838:
15834:
15829:
15824:
15820:
15816:
15809:
15801:
15797:
15793:
15789:
15785:
15781:
15776:
15771:
15767:
15763:
15756:
15748:
15746:0-521-38996-8
15742:
15738:
15734:
15733:
15725:
15717:
15713:
15709:
15705:
15701:
15697:
15692:
15687:
15683:
15679:
15672:
15664:
15658:
15654:
15653:
15645:
15637:
15631:
15627:
15623:
15622:
15614:
15601:on 2011-10-24
15600:
15596:
15592:
15586:
15579:
15573:
15569:
15568:
15560:
15552:
15546:
15542:
15541:
15533:
15518:
15517:
15510:
15495:
15494:
15487:
15479:
15473:
15469:
15468:
15460:
15452:
15448:
15444:
15440:
15432:
15424:
15418:
15414:
15413:
15405:
15397:
15393:
15388:
15383:
15379:
15375:
15371:
15367:
15360:
15352:
15348:
15344:
15340:
15333:
15325:
15319:
15315:
15314:
15306:
15298:
15296:9780521529273
15292:
15288:
15287:
15279:
15272:
15266:
15262:
15258:
15251:
15243:
15236:
15228:
15224:
15220:
15213:
15205:
15201:
15197:
15193:
15189:
15185:
15181:
15177:
15170:
15155:
15151:
15144:
15129:
15125:
15118:
15111:
15105:
15101:
15100:
15092:
15084:
15080:
15076:
15072:
15065:
15058:
15054:
15050:
15048:9780199214938
15044:
15040:
15039:
15031:
15029:
15027:
15018:
15014:
15010:
15003:
14995:
14991:
14986:
14981:
14977:
14973:
14968:
14963:
14959:
14955:
14948:
14940:
14936:
14932:
14928:
14923:
14918:
14914:
14910:
14903:
14895:
14891:
14887:
14883:
14876:
14863:on 2022-02-23
14862:
14858:
14854:
14848:
14846:
14844:
14842:
14840:
14838:
14836:
14834:
14832:
14830:
14828:
14826:
14824:
14822:
14820:
14805:
14801:
14795:
14781:
14775:
14771:
14767:
14766:
14758:
14744:
14742:0-470-09220-3
14738:
14734:
14730:
14729:
14721:
14713:
14709:
14703:
14695:
14691:
14686:
14681:
14677:
14673:
14669:
14665:
14658:
14651:
14645:
14641:
14634:
14626:
14622:
14617:
14612:
14608:
14604:
14599:
14594:
14590:
14586:
14579:
14571:
14565:
14561:
14560:
14552:
14543:
14538:
14534:
14530:
14526:
14522:
14515:
14508:
14500:
14496:
14492:
14488:
14484:
14480:
14473:
14465:
14463:9780521339070
14459:
14455:
14454:
14446:
14438:
14432:
14428:
14424:
14423:
14415:
14408:
14402:
14398:
14397:
14389:
14387:
14385:
14383:
14378:
14368:
14365:
14363:
14360:
14358:
14355:
14353:
14350:
14348:
14345:
14344:
14335:
14332:
14325:
14321:
14315:
14309:
14303:
14297:
14291:
14285:
14282:
14275:
14271:
14267:
14261:
14255:
14251:
14244:
14238:
14235:
14230:
14221:
14220:binary system
14217:
14213:
14209:
14205:
14202:
14195:
14191:
14185:
14179:
14178:
14175:
14164:
14155:
14149:
14143:
14139:
14136:
14129:
14125:
14119:
14115:
14111:
14105:
14102:
14095:
14089:
14085:
14079:
14071:
14070:
14067:
14063:
14059:
14050:
14043:
14039:
14033:
14027:
14023:
14020:
14013:
14009:
14002:
13996:
13993:
13992:variable star
13988:
13979:
13973:
13969:
13966:
13960:
13956:
13952:
13951:physical laws
13948:
13944:
13940:
13934:
13928:
13922:
13918:
13914:
13911:
13905:
13904:
13901:
13897:
13889:
13884:
13876:
13873:
13866:
13860:
13854:
13847:
13844:
13837:
13831:
13830:emission line
13827:
13823:
13821:spiral galaxy
13817:
13811:
13807:
13804:
13797:
13791:
13785:
13779:
13775:
13769:
13763:
13747:
13741:
13738:
13737:tropical year
13732:
13729:
13722:
13716:
13710:
13704:
13700:
13694:
13688:
13684:
13681:
13675:
13669:
13666:
13660:
13656:
13648:
13647:
13639:
13634:
13631:
13624:
13616:
13610:
13604:
13598:
13592:
13586:
13580:
13574:
13568:
13567:
13564:
13551:
13544:
13538:
13532:
13524:
13518:
13512:
13506:
13498:
13492:
13486:
13480:
13474:
13470:
13468:tidal braking
13464:
13461:
13460:tidal locking
13455:
13452:
13445:
13439:
13433:
13427:
13426:
13423:
13415:
13414:tidal braking
13408:
13402:
13396:
13390:
13384:
13381:
13375:
13372:
13364:
13361:
13354:
13348:
13342:
13336:
13333:
13326:
13320:
13314:
13308:
13302:
13296:
13293:
13286:
13282:
13278:
13274:
13268:
13265:telluric star
13261:
13258:
13251:
13249:proper motion
13245:
13239:
13233:
13229:
13223:
13214:
13211:
13204:
13198:
13192:
13186:
13180:
13177:
13170:
13164:
13160:
13154:
13148:
13146:same location
13142:
13136:
13130:
13127:
13120:
13114:
13108:
13102:
13096:
13090:
13084:
13080:
13074:
13068:
13062:
13056:
13055:
13052:
13044:
13037:
13031:
13025:
13019:
13013:
13007:
13004:
12989:
12983:
12979:
12973:
12967:
12963:
12959:
12952:
12946:
12940:
12934:
12928:
12923:An extremely
12922:
12919:
12912:
12906:
12904:galactic core
12900:
12894:
12888:
12884:
12877:
12876:
12869:
12865:
12860:
12856:
12852:
12846:
12843:
12837:
12834:
12828:
12825:
12818:
12812:
12806:
12801:), including
12800:
12794:
12790:
12784:
12783:
12780:
12772:
12765:
12759:
12753:
12750:
12743:
12739:
12734:that studies
12733:
12727:
12724:
12718:
12715:
12709:
12706:
12699:
12697:coronal loops
12693:
12687:
12681:
12677:
12673:
12670:
12663:
12657:
12655:astrophysical
12651:
12650:
12647:
12646:stellar model
12635:
12632:
12625:
12619:
12613:
12610:
12604:
12601:
12595:
12592:
12586:
12583:
12576:
12570:
12565:. The modern
12564:
12558:
12552:
12551:
12548:
12540:
12533:
12527:
12526:
12523:
12515:
12508:
12502:
12496:
12488:
12484:
12480:
12476:
12470:
12464:
12458:
12450:
12445:
12439:
12436:
12429:
12423:
12417:
12411:
12405:
12403:star clusters
12399:
12393:
12387:
12386:
12383:
12375:
12369:
12366:
12360:
12359:
12356:
12353:Also spelled
12348:
12341:
12335:
12329:
12325:
12321:
12317:
12311:
12307:
12303:
12299:
12296:
12273:
12269:
12265:
12261:
12260:
12257:
12244:
12235:
12230:
12224:
12221:
12220:spiral galaxy
12214:
12208:
12204:
12198:
12192:
12191:
12188:
12180:
12174:
12171:
12163:
12162:
12160:spectroscopic
12153:
12148:
12145:
12138:
12132:
12128:
12124:
12118:
12112:
12109:
12102:
12101:
12094:
12091:
12084:
12077:
12072:, called the
12071:
12069:June solstice
12065:
12059:
12053:
12047:
12044:
12037:
12031:
12025:
12019:
12013:
12007:
12003:
11999:
11995:
11992:
11985:
11979:
11977:sidereal time
11973:
11967:
11961:
11955:
11949:
11943:
11937:
11931:
11928:
11921:
11915:
11909:
11903:
11897:
11895:dwarf planets
11891:
11885:
11879:
11873:
11870:
11863:
11862:
11855:
11852:
11845:
11839:
11838:optical depth
11836:at which the
11835:
11829:
11823:
11812:
11805:
11799:
11793:
11787:
11781:
11778:
11771:
11764:
11751:
11745:
11734:
11728:
11725:
11724:solar granule
11719:
11716:
11709:
11705:
11699:
11695:
11691:
11685:
11682:
11675:
11669:
11663:
11656:
11650:
11644:
11638:
11632:
11629:
11628:solar eclipse
11622:
11619:
11613:
11607:
11601:
11595:
11589:
11583:
11577:
11571:
11565:
11559:
11556:
11550:
11546:
11539:
11538:
11531:
11525:
11519:
11513:
11509:
11505:
11502:
11496:
11493:
11492:sidereal year
11486:
11480:
11474:
11468:
11462:
11456:
11453:
11452:sidereal time
11446:
11440:
11434:
11428:
11422:
11419:
11412:
11406:
11400:
11394:
11388:
11382:
11376:
11373:
11366:
11365:
11363:March equinox
11358:
11354:
11350:
11346:
11340:
11334:
11333:
11330:
11322:
11315:
11309:
11304:
11298:
11294:
11293:
11290:
11282:
11275:
11272:
11271:semi-diameter
11265:
11259:
11256:selenocentric
11251:
11245:
11241:
11237:
11234:
11227:
11219:
11213:
11209:
11205:
11199:
11193:
11192:
11189:
11181:
11180:scintillation
11175:
11172:
11165:
11159:
11155:
11151:
11145:
11142:
11135:
11129:
11126:Saber's beads
11123:
11114:
11110:
11106:
11100:
11094:
11086:
11080:
11074:
11068:
11062:
11059:
11052:
11051:
11049:optical depth
11044:
11038:
11032:
11028:
11025:
11018:
11012:
11006:
11000:
10994:
10988:
10987:
10984:
10980:
10979:orphan planet
10976:
10972:
10964:
10957:
10953:
10947:
10941:
10938:
10931:
10930:
10923:
10919:
10917:giant planets
10913:
10907:
10901:
10895:
10889:
10883:
10880:
10873:
10867:
10863:
10857:
10854:
10846:
10845:
10837:
10831:
10830:
10823:
10817:
10813:
10807:
10804:
10796:
10793:
10787:
10784:
10777:
10771:
10765:
10761:
10755:
10749:
10743:
10737:
10734:
10728:
10725:
10718:
10714:
10713:helium fusion
10709:
10705:
10699:
10693:
10690:
10683:
10677:
10673:
10667:
10664:
10657:
10653:
10649:
10645:
10640:that studies
10639:
10633:
10630:
10623:
10619:
10613:
10609:
10606:
10601:
10592:
10588:
10584:
10580:
10576:
10572:
10566:
10560:
10554:
10548:
10547:
10545:
10537:
10528:
10527:
10519:
10513:
10507:
10501:
10495:
10489:
10483:
10480:
10473:
10470:
10466:
10462:
10458:
10452:
10443:
10437:
10431:
10428:
10421:
10417:
10413:
10409:
10401:
10397:
10394:
10388:
10385:
10378:
10376:planetesimals
10372:
10366:
10360:
10354:
10351:
10344:
10341:
10340:proper motion
10334:
10333:line-of-sight
10330:
10324:
10318:
10314:
10306:
10305:
10298:
10292:
10288:
10282:
10281:
10278:
10277:direct motion
10270:
10263:
10257:
10256:
10253:
10249:
10245:
10237:
10231:
10228:
10221:
10217:
10213:
10209:
10203:
10197:
10194:
10187:
10181:
10175:
10171:
10165:
10162:
10155:
10149:
10143:
10140:
10133:
10127:
10121:
10115:
10109:
10105:
10099:
10096:
10090:
10089:
10086:
10082:
10073:
10066:
10060:
10058:planetesimals
10054:
10048:
10042:
10036:
10034:dwarf planets
10030:
10024:
10018:
10012:
10006:
10000:
9996:
9993:
9986:
9980:
9974:
9968:
9967:
9964:
9956:
9949:
9945:
9939:
9933:
9929:
9926:
9919:
9916:
9909:
9907:planetesimals
9903:
9897:
9891:
9885:
9879:
9875:
9869:
9868:
9865:
9857:
9850:
9844:
9836:
9832:
9830:planetesimals
9826:
9820:
9816:
9812:
9808:
9803:
9797:
9794:
9787:
9781:
9773:
9767:
9761:
9755:
9749:
9743:
9737:
9733:
9732:
9729:
9721:
9715:
9712:
9706:
9703:
9696:
9692:
9688:
9682:
9678:
9672:
9666:
9663:
9656:
9651:
9645:
9639:
9633:
9627:
9624:
9617:
9616:
9609:
9603:
9600:
9593:
9592:
9585:
9579:
9573:
9570:
9563:
9562:
9555:
9549:
9548:
9545:
9537:
9530:
9526:
9522:
9515:
9512:
9505:
9501:
9498:of the words
9497:
9493:
9487:
9481:
9477:
9471:
9467:
9459:
9453:
9452:
9444:
9440:
9431:
9425:
9421:
9415:
9411:
9410:
9407:
9399:
9392:
9388:
9386:perturbations
9382:
9376:
9370:
9367:
9361:
9353:
9347:
9341:
9335:
9329:
9325:
9322:
9321:orbital speed
9314:
9313:
9304:
9298:
9292:
9286:
9282:
9279:
9273:
9267:
9263:
9257:
9251:
9245:
9239:
9233:
9230:
9223:
9217:
9211:
9205:
9201:
9195:
9189:
9183:
9179:
9176:
9175:orbital plane
9169:
9163:
9157:
9151:
9145:
9144:
9141:
9133:
9126:
9120:
9114:
9108:
9102:
9096:
9090:
9084:
9081:
9075:
9072:
9065:
9059:
9057:orbital plane
9053:
9047:
9044:
9036:
9030:
9028:orbital plane
9024:
9023:
9015:
9009:
9003:
9000:
8993:
8987:
8981:
8978:
8971:
8967:
8961:
8955:
8954:
8951:
8937:
8931:
8925:
8919:
8913:
8907:
8901:
8897:
8894:
8886:
8883:
8876:
8870:
8867:
8860:
8856:
8853:
8846:
8840:
8836:
8830:
8824:
8822:planetesimals
8818:
8817:
8814:
8806:
8799:
8793:
8787:
8781:
8775:
8772:
8765:
8759:
8753:
8747:
8741:
8738:
8732:
8729:
8722:
8716:
8710:
8704:
8698:
8692:
8686:
8680:
8679:
8676:
8668:
8661:
8660:
8653:
8650:
8643:
8637:
8631:
8628:
8621:
8620:variable star
8617:
8613:
8609:
8606:A diagram of
8605:
8599:
8590:
8584:
8578:
8572:
8569:
8562:
8559:
8552:
8548:
8541:
8535:
8529:
8523:
8517:
8513:
8507:
8504:
8497:
8491:
8485:
8479:
8473:
8467:
8464:is below the
8463:
8457:
8453:
8447:
8444:
8438:
8434:
8427:
8421:
8417:
8413:
8407:
8404:
8396:
8393:
8386:
8380:
8378:star clusters
8374:
8368:
8367:ionized gases
8364:
8360:
8356:
8350:
8344:
8338:
8335:
8328:
8322:
8316:
8310:
8306:
8300:
8295:, such as an
8294:
8288:
8284:
8277:
8271:
8265:
8259:
8253:
8247:
8246:
8243:
8235:
8227:
8226:
8223:
8219:
8211:
8204:
8198:
8192:
8186:
8183:
8176:
8172:
8168:
8164:
8160:
8156:
8150:
8142:
8139:
8132:
8126:
8120:
8116:
8112:
8106:
8100:
8094:
8091:
8084:
8078:
8072:
8066:
8065:
8062:
8054:
8047:
8041:
8035:
8034:
8031:
8023:
8022:morning width
8017:
8016:
8013:
8005:
7998:
7997:
7990:
7987:
7980:
7979:
7972:
7971:
7964:
7958:
7952:
7946:
7940:
7939:
7936:
7932:
7924:
7917:
7913:
7907:
7901:
7895:
7893:tidal locking
7889:
7883:
7877:
7874:
7867:
7866:
7859:
7856:
7849:
7848:
7845:
7837:
7830:
7826:
7820:
7817:
7810:
7809:
7802:
7801:
7794:
7788:
7782:
7779:
7772:
7766:
7760:
7754:
7748:
7742:
7739:
7732:
7731:
7724:
7721:
7713:
7710:
7708:constellation
7704:
7703:
7696:
7689:
7683:
7680:
7674:
7667:
7661:
7655:
7649:
7643:
7638:
7636:barred spiral
7632:
7629:
7622:
7616:
7610:
7608:variable star
7604:
7601:microvariable
7596:
7590:
7585:A very small
7584:
7581:
7574:
7568:
7564:
7560:
7555:A very small
7554:
7551:
7544:
7540:
7536:
7533:
7526:
7520:
7514:
7508:
7502:
7499:
7498:meteor shower
7492:
7486:
7480:
7477:
7470:
7464:
7461:
7454:
7453:incandescence
7450:
7444:
7438:
7432:
7426:
7420:
7419:
7416:
7412:
7411:shooting star
7404:
7397:
7391:
7387:
7381:
7375:
7372:
7365:
7359:
7354:and of their
7353:
7347:
7341:
7333:
7327:
7321:
7318:
7311:
7310:
7303:
7295:
7289:
7283:
7277:
7271:
7265:
7259:
7253:
7247:
7242:
7237:
7230:
7229:
7222:
7218:
7214:
7210:
7204:
7198:
7197:
7194:
7186:
7185:March equinox
7179:
7178:
7171:
7168:
7161:
7155:
7151:
7147:
7143:
7137:
7131:
7125:
7122:
7121:main sequence
7115:
7111:
7105:
7101:
7098:
7091:
7085:
7079:
7073:
7070:
7069:magnetosphere
7063:
7061:rogue planets
7057:
7051:
7049:neutron stars
7045:
7039:
7033:
7029:
7025:
7019:
7015:
7010:
7000:
6999:
6991:
6985:
6979:
6973:
6969:
6965:
6959:
6953:
6951:synodic month
6947:
6941:
6940:
6937:
6929:
6922:
6916:
6908:
6902:
6896:
6892:
6888:
6884:
6878:
6872:
6866:
6863:
6856:
6850:
6844:
6838:
6832:
6826:
6822:
6816:
6813:
6806:
6800:
6794:
6788:
6782:
6775:of the image.
6774:
6773:
6768:
6762:
6759:
6752:
6746:
6740:
6718:
6712:
6706:
6702:
6695:
6694:
6689:
6685:
6681:
6675:
6672:
6666:
6663:
6657:
6656:
6653:
6649:
6645:
6637:
6630:
6624:
6618:
6611:
6603:
6599:
6595:
6590:
6584:
6578:
6577:
6574:
6570:
6566:
6558:
6553:
6544:
6540:
6538:dwarf planets
6534:
6532:asteroid belt
6528:
6522:
6516:
6511:in the outer
6510:
6504:
6498:
6492:
6486:
6480:
6479:
6476:
6468:
6461:
6459:perturbations
6455:
6453:orbital plane
6449:
6445:
6441:
6437:
6431:
6430:
6427:
6419:
6413:
6410:
6405:
6396:
6390:
6384:
6382:tropical year
6377:
6373:
6369:
6362:
6356:
6353:
6348:
6339:
6333:
6327:
6321:
6318:
6311:
6307:
6305:regular moons
6301:
6295:
6289:
6283:
6277:
6271:
6268:
6262:
6259:
6253:
6250:
6243:
6237:
6233:
6227:
6221:
6220:
6217:
6216:Laplace plane
6213:
6205:
6198:
6192:
6186:
6183:
6176:
6172:
6168:
6162:
6156:
6152:
6148:
6142:
6138:
6131:
6127:
6122:that studies
6121:
6115:
6112:
6105:
6101:
6095:
6091:
6086:
6082:
6076:
6072:
6068:
6065:
6058:
6057:
6050:
6047:
6040:
6034:
6030:
6026:
6020:
6016:
6012:
6008:
6004:
6000:
5996:
5990:
5987:
5982:
5973:
5969:
5963:
5957:
5953:
5947:
5941:
5933:
5927:
5921:
5915:
5907:
5903:
5897:
5893:
5889:
5885:
5877:
5871:
5865:
5859:
5853:
5849:
5846:
5839:
5833:
5827:
5821:
5817:
5811:
5805:
5799:
5793:
5787:
5784:
5777:
5771:
5767:
5764:
5757:
5755:galactic core
5751:
5745:
5739:
5738:
5735:
5727:
5720:
5714:
5708:
5706:main-sequence
5702:
5696:
5690:
5684:
5682:spectral type
5678:
5672:
5666:
5660:
5654:
5648:
5645:
5638:
5632:
5626:
5620:
5614:
5611:
5605:
5602:
5595:
5589:
5583:
5580:
5573:
5569:
5563:
5559:
5551:
5545:
5538:
5534:
5531:
5527:
5523:
5517:
5514:
5509:
5500:
5494:
5488:
5482:
5480:neutron stars
5476:
5472:
5468:
5462:
5459:
5452:
5451:Einstein ring
5448:
5447:
5439:
5433:
5429:
5423:
5420:
5414:
5411:
5404:
5402:open clusters
5398:
5392:
5390:galactic core
5386:
5380:
5374:
5371:
5364:
5358:
5352:
5346:
5343:
5336:
5330:
5324:
5318:
5312:
5306:
5300:
5296:
5289:
5283:
5279:
5273:
5267:
5262:
5256:
5255:
5252:
5248:
5240:
5233:
5227:
5221:
5215:
5209:
5201:
5197:
5193:
5187:
5184:
5177:
5171:
5165:
5159:
5151:
5147:
5141:
5138:
5131:
5127:
5123:
5120:
5113:
5107:
5103:
5099:
5095:
5091:
5085:
5082:
5075:
5073:neutron stars
5069:
5063:
5057:
5051:
5047:
5043:
5036:
5032:
5027:that studies
5026:
5020:
5017:
5010:
5006:
5002:
4998:
4994:
4990:
4986:
4980:
4977:
4970:
4968:superclusters
4964:
4958:
4952:
4946:
4945:
4942:
4934:
4927:
4925:superclusters
4921:
4919:galaxy groups
4915:
4913:star clusters
4909:
4903:
4897:
4894:
4887:
4881:
4875:
4869:
4863:
4857:
4851:
4845:
4839:
4833:
4827:
4821:
4818:
4811:
4805:
4799:
4795:
4789:
4783:
4777:
4771:
4763:
4757:
4751:
4747:
4741:
4738:
4737:galactic tide
4731:
4725:
4719:
4713:
4707:
4701:
4695:
4694:
4691:
4687:
4686:galactic year
4679:
4672:
4666:
4660:
4654:
4648:
4642:
4641:
4638:
4634:
4633:galactic core
4626:
4620:
4617:
4611:
4608:
4601:
4597:
4593:
4590:
4584:
4578:
4572:
4567:
4561:
4555:
4552:
4545:
4542:
4540:constellation
4536:
4530:
4524:
4518:
4515:
4508:
4502:
4497:
4491:
4488:
4483:
4474:
4468:
4465:
4458:
4452:
4448:
4444:
4440:
4436:
4434:variable star
4430:
4427:
4420:
4414:
4408:
4402:
4396:
4390:
4384:
4378:
4377:
4374:
4366:
4359:
4353:
4347:
4341:
4338:
4336:constellation
4332:
4326:
4320:
4314:
4311:
4304:
4298:
4292:
4286:
4280:
4277:
4275:constellation
4271:
4265:
4259:
4257:March equinox
4253:
4252:
4249:
4248:Cusp of Aries
4240:
4233:
4229:
4226:
4219:
4213:
4207:
4204:
4197:
4191:
4190:line of sight
4187:
4181:
4173:
4167:
4164:
4157:
4151:
4145:
4139:
4135:
4129:
4123:
4120:
4115:
4106:
4105:
4098:
4090:
4084:
4078:
4077:
4074:
4066:
4059:
4053:
4047:
4041:
4035:
4032:
4025:
4019:
4014:
4008:
4005:
3998:
3994:
3990:
3984:
3980:
3976:
3972:
3969:
3961:
3960:
3952:
3946:
3940:
3934:
3928:
3922:
3919:
3912:
3906:
3902:
3898:
3893:
3890:
3883:
3882:
3875:
3869:
3863:
3857:
3851:
3845:
3839:
3833:
3827:
3821:
3815:
3812:
3805:
3799:
3791:
3785:
3779:
3774:(forming the
3773:
3767:
3761:
3757:
3751:
3748:
3741:
3735:
3731:
3725:
3721:
3715:
3712:
3704:
3702:perturbations
3698:
3692:
3686:
3680:
3677:
3670:
3664:
3658:
3652:
3649:
3642:
3636:
3630:
3626:
3623:
3615:
3614:
3606:
3600:
3596:
3590:
3584:
3578:
3572:
3571:
3568:
3560:
3553:
3547:
3541:
3537:
3531:
3528:
3521:
3517:
3513:
3510:
3503:
3497:
3491:
3485:
3479:
3473:
3467:
3463:
3457:
3451:
3445:
3442:
3434:
3427:
3421:
3415:
3409:
3408:
3400:
3395:of the Earth.
3394:
3388:
3382:
3376:
3370:
3364:
3358:
3352:
3351:Earth's orbit
3348:
3344:
3343:
3340:
3336:
3328:
3321:
3320:
3313:
3310:
3302:
3296:
3293:
3288:
3279:
3273:
3267:
3261:
3255:
3251:
3247:
3244:
3238:
3232:
3230:main-sequence
3226:
3220:
3217:
3211:
3208:
3201:
3194:
3188:
3185:
3178:
3174:
3168:
3162:
3156:
3150:
3144:
3138:
3135:
3128:
3127:
3120:
3117:
3116:direct motion
3110:
3104:
3098:
3092:
3088:
3082:
3076:
3070:
3064:
3063:
3060:
3056:
3048:
3041:
3040:
3033:
3027:
3021:
3015:
3014:
3011:
3003:
2996:
2990:
2984:
2978:
2972:
2968:
2965:
2958:
2952:
2946:
2944:star clusters
2940:
2934:
2928:
2922:
2916:
2910:
2906:
2899:
2895:
2889:
2883:
2880:
2873:
2872:
2865:
2859:
2855:
2849:
2846:
2838:
2834:
2833:
2825:
2819:
2815:
2813:planetesimals
2809:
2803:
2800:
2795:
2786:
2782:
2778:
2772:
2768:
2762:
2756:
2750:
2748:constellation
2744:
2738:
2732:
2726:
2720:
2714:
2713:
2710:
2702:
2695:
2694:
2687:
2681:
2678:balances the
2677:
2673:
2672:
2669:
2657:
2649:
2643:
2639:
2636:
2629:
2625:
2619:
2616:
2609:
2603:
2597:
2593:
2589:
2586:
2580:
2579:
2576:
2567:
2560:
2554:
2551:
2550:
2547:
2539:
2533:
2530:
2523:
2517:
2511:
2505:
2499:
2495:
2491:
2485:
2482:
2475:
2473:solar eclipse
2469:
2463:
2459:
2456:
2449:
2448:
2441:
2435:
2431:
2425:
2422:
2421:constellation
2415:
2409:
2403:
2399:
2393:
2390:
2383:
2382:
2375:
2372:
2365:
2359:
2353:
2351:neutron stars
2347:
2341:
2335:
2334:
2331:
2323:
2316:
2312:
2306:
2304:proper motion
2300:
2296:
2288:
2284:
2280:
2277:
2273:
2267:
2264:
2257:
2253:
2249:
2245:
2239:
2236:
2229:
2226:bands of the
2225:
2221:
2218:
2212:
2209:
2203:
2196:
2195:
2192:
2189:Also spelled
2184:
2176:
2167:
2164:
2160:
2156:
2155:H and K lines
2152:
2148:
2143:
2134:
2125:
2119:
2115:
2108:
2105:
2098:
2092:
2086:
2080:
2076:
2069:
2067:giant planets
2063:
2057:
2051:
2045:
2039:
2033:
2031:outer planets
2027:
2021:
2015:
2009:
2006:
1999:
1993:
1987:
1981:
1978:
1971:
1965:
1959:
1953:
1947:
1941:
1938:
1931:
1930:
1923:
1920:
1913:
1907:
1901:
1895:
1889:
1883:
1879:
1873:
1870:
1862:
1856:
1850:
1844:
1843:
1836:
1829:
1823:
1817:
1811:
1805:
1799:
1793:
1789:
1786:
1779:
1775:
1771:
1767:
1759:
1756:
1751:
1743:
1740:
1733:
1729:
1723:
1721:main sequence
1717:
1713:
1709:
1703:
1700:
1693:
1689:
1685:
1684:
1681:
1677:
1676:
1661:
1658:
1651:
1649:event horizon
1645:
1642:
1635:
1631:
1625:
1619:
1613:
1607:
1604:
1597:
1591:
1585:
1582:
1575:
1571:
1568:
1561:
1555:
1549:
1543:
1539:
1533:
1529:
1523:
1519:
1516:
1508:
1502:
1501:
1493:
1489:
1480:
1476:
1472:
1468:
1465:
1459:
1456:
1449:
1443:
1439:
1433:
1431:orbital plane
1427:
1421:
1420:
1417:
1409:
1402:
1396:
1390:
1386:
1380:
1376:
1370:
1364:
1358:
1354:
1348:
1342:
1336:
1333:
1325:
1322:
1315:
1309:
1305:
1301:
1297:
1293:
1287:
1283:
1279:
1276:
1270:
1267:
1260:
1254:
1248:
1245:
1230:
1229:Earth's orbit
1226:
1222:
1216:
1212:
1205:
1199:
1195:
1191:
1185:
1179:
1174:
1168:
1162:
1156:
1150:
1144:
1141:
1134:
1128:
1122:
1116:
1110:
1104:
1098:
1097:
1094:
1086:
1079:
1078:
1075:
1072:Also spelled
1067:
1060:
1054:
1048:
1042:
1036:
1030:
1024:
1023:
1020:
1012:
1005:
999:
993:
990:
983:
982:
975:
969:
967:binary system
963:
960:
952:
951:
948:
940:
933:
932:
925:
922:
921:astrodynamics
915:
914:biosignatures
911:
907:
901:
897:
893:
889:
883:
882:
879:
871:
864:
860:
856:
854:minor planets
850:
844:
838:
834:
830:
824:
818:
815:
814:asteroid belt
808:
802:
800:planetesimals
796:
790:
784:
778:
772:
768:
762:
757:of the inner
756:
750:
747:
740:
738:constellation
734:
728:
722:
719:
712:
706:
700:
694:
686:
685:
678:
672:
666:
660:
654:
648:
647:
644:
636:
629:
628:
621:
615:
609:
606:
599:
593:
587:
581:
575:
574:
571:
567:
559:
552:
546:
540:
534:
528:
522:
516:
513:
506:
503:
496:
492:
491:
488:
480:
473:
472:
465:
459:
453:
450:
443:
442:
435:
429:
426:
419:
418:
411:
405:
402:
395:
394:
387:
381:
377:
374:
367:
361:
358:
350:
346:
345:
338:
334:
328:
324:
318:
314:
308:
302:
298:
295:
288:
287:active galaxy
284:
278:
274:
268:
262:
258:
251:
245:
239:
233:
230:
223:
217:
211:
205:
199:
196:
189:
183:
181:main-sequence
177:
171:
168:
163:
153:
150:
148:
145:
143:
140:
138:
135:
132:
129:
126:
123:
120:
117:
114:
111:
108:
105:
102:
99:
96:
93:
90:
87:
84:
81:
78:
75:
72:
69:
66:
63:
60:
59:
51:
49:
45:
41:
37:
33:
19:
16904:Engineering
16855:Cell biology
16834:
16825:Architecture
16577:
16557:Astrophysics
16536:Astrobiology
16200:Far-infrared
16154:Local system
16089:Astronomy by
16079:... in space
16071:
15976:, retrieved
15971:
15958:, retrieved
15953:
15940:, retrieved
15935:
15922:, retrieved
15916:
15906:, retrieved
15901:
15868:
15861:
15818:
15814:
15808:
15765:
15761:
15755:
15731:
15724:
15681:
15677:
15671:
15651:
15644:
15620:
15613:
15603:, retrieved
15599:the original
15594:
15585:
15566:
15559:
15539:
15532:
15521:, retrieved
15515:
15509:
15498:, retrieved
15492:
15486:
15466:
15459:
15442:
15438:
15431:
15411:
15404:
15369:
15365:
15359:
15342:
15338:
15332:
15312:
15305:
15285:
15278:
15256:
15250:
15241:
15235:
15218:
15212:
15179:
15175:
15169:
15158:, retrieved
15153:
15143:
15132:, retrieved
15127:
15117:
15098:
15091:
15074:
15070:
15064:
15037:
15008:
15002:
14957:
14953:
14947:
14912:
14908:
14902:
14885:
14881:
14875:
14865:, retrieved
14861:the original
14856:
14808:, retrieved
14806:, 2017-02-14
14803:
14794:
14783:, retrieved
14764:
14757:
14746:, retrieved
14727:
14720:
14707:
14702:
14667:
14663:
14657:
14639:
14633:
14588:
14584:
14578:
14558:
14551:
14524:
14520:
14507:
14482:
14478:
14472:
14452:
14445:
14421:
14414:
14395:
14212:neutron star
14206:A source of
14201:X-ray source
14173:
14170:
14065:
14061:
14057:
14054:
13958:
13899:
13895:
13892:
13852:astronomical
13789:mean anomaly
13746:true anomaly
13642:
13608:eccentricity
13587:), used for
13562:
13559:
13529:tilt erosion
13519:such as the
13507:A stream of
13503:tidal stream
13431:tidal forces
13421:
13418:
13184:conjunctions
13176:synodic time
13106:eccentricity
13094:sidereal day
13050:
13047:
12944:evolutionary
12871:
12833:supercluster
12804:brown dwarfs
12798:solar masses
12778:
12775:
12749:subsatellite
12645:
12644:Also simply
12642:
12546:
12543:
12521:
12518:
12381:
12378:
12365:star cluster
12355:star catalog
12354:
12351:
12262:The nominal
12255:
12252:
12242:
12233:
12193:A branch of
12186:
12183:
12157:
12144:spectroscopy
12096:
11869:Solar System
11857:
11811:solar radius
11681:solar facula
11617:
11599:sidereal day
11533:
11478:sidereal day
11432:Solar System
11372:sidereal day
11360:
11356:
11352:
11328:
11325:
11307:Kepler orbit
11288:
11285:
11187:
11184:
11084:sidereal day
11046:
10982:
10978:
10975:nomad planet
10974:
10970:
10967:
10963:rogue planet
10925:
10840:
10825:
10818:such as the
10766:about their
10763:
10733:regular moon
10663:radio source
10585:, and their
10543:
10540:
10522:
10469:longitudinal
10435:neutron star
10322:double stars
10300:
10293:such as the
10276:
10273:
10252:central body
10251:
10248:primary body
10247:
10243:
10240:
10211:
10153:dwarf planet
10147:minor planet
10119:debris disks
10095:planetesimal
10084:
10080:
10077:
10064:debris discs
9962:
9959:
9895:dwarf planet
9863:
9860:
9834:
9727:
9724:
9643:Kepler orbit
9623:perturbation
9611:
9587:
9557:
9543:
9540:
9503:
9499:
9447:
9414:nearly empty
9405:
9402:
9374:Kepler orbit
9308:
9277:dwarf planet
9265:
9249:eccentricity
9221:Solar System
9161:Solar System
9139:
9136:
9080:orbital node
9018:
8950:orbital plot
8949:
8946:
8866:open cluster
8844:Solar System
8812:
8809:
8690:Solar System
8684:observations
8674:
8671:
8655:
8611:
8607:
8411:compact star
8403:neutron star
8365:, and other
8269:minor planet
8241:
8238:
8221:
8217:
8214:
8060:
8057:
8053:moving group
8029:
8026:
8011:
8008:
7995:subsatellite
7992:
7977:subsatellite
7974:
7966:
7962:minor planet
7956:dwarf planet
7934:
7930:
7927:
7915:
7861:
7843:
7840:
7807:subsatellite
7804:
7796:
7792:minor planet
7738:minor planet
7726:
7698:
7675:, which the
7647:Solar System
7503:A series of
7415:falling star
7414:
7410:
7407:
7305:
7287:true anomaly
7278:in the same
7240:
7236:mean anomaly
7224:
7220:
7216:
7192:
7189:
7173:
7102:A numerical
7055:brown dwarfs
7032:galaxy halos
6994:
6971:
6967:
6935:
6932:
6770:
6691:
6651:
6647:
6643:
6640:
6613:
6606:
6572:
6568:
6564:
6561:
6541:, including
6514:Solar System
6474:
6471:
6425:
6422:
6418:Kepler orbit
6331:evolutionary
6309:
6284:, and often
6215:
6211:
6208:
6132:wavelengths.
6052:
6038:Solar System
5994:giant planet
5931:brown dwarfs
5852:great circle
5788:For a given
5733:
5730:
5636:Solar System
5579:heliocentric
5560:The precise
5526:O-type stars
5463:A branch of
5442:
5431:
5353:, including
5342:giant planet
5322:sidereal day
5250:
5246:
5243:
5111:Solar System
5089:giant planet
5037:wavelengths.
4940:
4937:
4933:galaxy group
4758:such as the
4723:Solar System
4689:
4685:
4682:
4636:
4632:
4629:
4582:solar masses
4394:Solar System
4372:
4369:
4247:
4244:
4195:star cluster
4163:field galaxy
4149:solar facula
4103:astrobiology
4100:
4088:Solar System
4072:
4069:
4045:Solar System
3955:
3877:
3867:September 22
3786:towards the
3631:between the
3609:
3576:Kepler orbit
3566:
3563:
3501:inclinations
3480:towards the
3455:Solar System
3403:
3374:Solar System
3338:
3334:
3331:
3315:
3309:eccentricity
3277:brown dwarfs
3265:white dwarfs
3207:dwarf planet
3189:Any pair of
3176:
3122:
3080:Solar System
3074:minor planet
3058:
3054:
3051:
3035:
3034:). Contrast
3031:Solar System
3019:orbital node
3009:
3006:
2982:neutron star
2926:Solar System
2867:
2831:debris disks
2828:
2784:
2780:
2770:
2708:
2705:
2689:
2667:
2664:
2607:Solar System
2574:
2571:
2545:
2542:
2481:coronal loop
2443:
2410:or the same
2377:
2345:white dwarfs
2329:
2326:
2322:compact star
2190:
2187:
2171:
2159:photospheric
2149:of a star's
2138:
2129:
2123:chromosphere
2120:in a star's
2104:chromosphere
1925:
1890:, including
1838:
1794:of a body's
1792:great circle
1770:spectrograph
1679:
1671:
1668:
1567:baryogenesis
1496:
1415:
1412:
1389:polar motion
1275:astrophysics
1220:Solar System
1160:Solar System
1120:star cluster
1092:
1089:
1073:
1070:
1018:
1015:
977:
946:
943:
939:astrogeology
927:
900:habitability
877:
874:
870:astrobiology
862:
858:
828:Solar System
760:Solar System
754:minor planet
680:
664:Solar System
652:orbital node
642:
639:
623:
619:Solar System
569:
565:
562:
486:
483:
467:
437:
413:
389:
385:A-type stars
340:
337:Syrtis Major
309:, such as a
286:
31:
29:
17025:Ornithology
17010:Meteorology
16995:Mathematics
16985:Ichthyology
16820:Archaeology
16815:Agriculture
16799:engineering
16624:Planetarium
16281:High-energy
16267:Cosmic rays
16219:Ultraviolet
15345:: 126–140,
15182:: 681–694,
15128:www.gnu.org
15077:: 503–511,
14915:, id. A29,
14485:: 763–777,
14310:across the
14101:white dwarf
13714:occultation
13621:topocentric
13614:inclination
13451:tidal force
13300:heliosphere
13078:fixed stars
13043:synodic day
12950:white dwarf
12892:black holes
12870:. Contrast
12623:binary star
12506:star system
12459:Any set of
12397:binary star
12374:star system
12318:due to the
12315:outer space
12116:binary star
11851:solar storm
11833:photosphere
11797:photosphere
11715:solar flare
11689:photosphere
11636:occultation
11593:fixed stars
11563:synodic day
11532:. See also
11517:outer space
11466:fixed stars
11438:fixed stars
11389:of its own
11386:fixed stars
11313:binary star
11078:synodic day
10945:tidal force
10937:Roche limit
10924:. See also
10879:ring system
10824:. Contrast
10821:fixed stars
10717:core region
10676:radio waves
10587:ultraviolet
10579:radio waves
10441:white dwarf
10350:protoplanet
10299:. Contrast
10296:fixed stars
10179:inclination
10161:polar orbit
10131:protoplanet
10022:star system
9997:Any set of
9963:planetology
9948:Ring Nebula
9898:, or other
9851:or planets.
9833:. The term
9813:by its own
9785:inclination
9747:inclination
9711:photosphere
9662:phase angle
9556:. Contrast
9529:light curve
9496:portmanteau
9485:light-years
9398:outer space
9261:inclination
9196:around its
8939:trajectory.
8771:occultation
8720:uncertainty
8602:O–C diagram
8458:, when the
8398:undetected.
8222:unaided eye
8169:. Most are
8130:cosmic rays
7965:. See also
7959:, or other
7947:orbiting a
7795:. See also
7749:around the
7712:Sagittarius
7691:The bright
7665:light-years
7572:cosmic dust
7532:metallicity
7348:across the
7104:logarithmic
7052:as well as
7043:black holes
7028:dark matter
6928:lunar phase
6879:, or other
6812:Local Group
6716:Julian year
6467:Kuiper belt
6368:Julian year
6046:inclination
5938:hypergalaxy
5892:Delta Scuti
5845:hour circle
5815:hour circle
5734:Hill radius
5726:Hill sphere
5718:white dwarf
5700:metallicity
5676:color index
5610:heliosphere
5556:heliocenter
5530:Ultraviolet
5518:An ionized
5513:H II region
5486:black holes
5191:phase angle
5055:light-years
4849:dark matter
4798:kiloparsecs
4793:light-years
4745:tidal force
4714:around the
4690:cosmic year
4592:Sagittarius
4431:A class of
4365:fixed stars
4203:first light
4133:photosphere
3997:attenuation
3796:equinoctial
3540:ellipsoidal
3353:around the
3246:giant stars
3199:binary star
3184:double star
2976:white dwarf
2845:declination
2799:debris disk
2701:culmination
2688:. See also
2558:outer space
2538:cosmic dust
2515:solar flare
2460:An aura of
2389:conjunction
2357:black holes
2217:color index
2037:Kuiper belt
1963:fixed stars
1774:Coudé focus
1699:brown dwarf
1629:double star
1611:star system
1603:binary star
1520:The common
1506:binary star
1304:temperature
892:abiogenesis
701:or Earth's
622:. Contrast
436:. Contrast
392:metallicity
327:cloud cover
221:light-years
167:A-type star
17080:Categories
17040:Psychiatry
16949:Geography
16920:Entomology
16617:Photometry
16594:Binoculars
16571:Astrometry
16432:telescopes
16329:Babylonian
16173:EM methods
16051:Astronomer
15978:2012-02-20
15960:2018-03-09
15950:"Glossary"
15942:2018-03-09
15924:2018-03-09
15908:2012-02-19
15879:038794138X
15605:2012-02-27
15550:0521780918
15523:2011-10-20
15500:2011-10-20
15270:0486646874
15160:19 January
15134:19 January
14967:1805.12143
14922:1609.02864
14867:2021-11-22
14810:2019-03-09
14785:2016-10-15
14770:OUP Oxford
14748:2012-02-29
14373:References
14216:black hole
14106:A type of
14051:(Virgo SC)
13977:multiverse
13949:, and the
13849:including
13815:luminosity
13698:luminosity
13406:halo stars
13332:terminator
13318:solar wind
13112:axial tilt
13063:(i.e. its
12859:geocentric
12574:luminosity
12479:Betelgeuse
12336:, and its
12333:luminosity
12288: ft/s
12212:astrometry
12113:A type of
11991:solar wind
11927:solar time
11733:solar mass
11703:solar limb
11512:atmosphere
11349:North Pole
11302:elliptical
11208:turbulence
11197:brightness
11104:star spots
11098:luminosity
11036:atmosphere
10902:such as a
10843:retrograde
10558:luminosity
10525:quadrature
10493:elongation
10479:quadrature
10420:periastron
10261:barycenter
10193:precession
10052:meteoroids
10001:bound non-
9930:A type of
9821:) and has
9798:A type of
9670:elongation
9599:perihelion
9544:pericenter
9412:The vast,
9339:barycenter
8943:orbit plot
8882:opposition
8859:convection
8805:Oort cloud
8751:telescopes
8675:arc length
8658:axial tilt
8612:calculated
8588:precession
8539:retrograde
8486:, and the
8408:A type of
8372:luminosity
8138:multiverse
8110:extrasolar
8095:A type of
8030:rise width
7931:minor moon
7720:minor axis
7614:luminosity
7484:atmosphere
7448:atmosphere
7269:pericenter
7213:North Pole
7167:major axis
7154:hydrogen-1
7135:luminosity
7077:solar wind
7020:A kind of
6936:Moon phase
6862:luminosity
6744:astrometry
6733:10 mi
6725:10 km
6701:light-year
6394:light-year
6293:retrograde
6249:ionosphere
6225:barycenter
6190:extinction
6102:, such as
6085:geocentric
5956:elliptical
5919:luminosity
5783:hour angle
5749:satellites
5652:luminosity
5649:A plot of
5601:heliopause
5495:, and the
5492:supernovae
5362:ice giants
5356:gas giants
5231:aberration
5225:light-time
5200:Lambertian
5137:geocentric
4861:elliptical
4658:luminosity
4464:Fulton gap
4456:red dwarfs
4426:flare star
4412:extrasolar
4348:meets the
4293:meets the
4178:field star
4155:solar limb
4140:. For the
4095:exobiology
3979:scattering
3975:absorption
3968:extinction
3944:luminosity
3622:elongation
3573:A type of
3532:A type of
3516:black body
3392:axial tilt
3250:Betelgeuse
3216:dwarf star
3145:(e.g. the
3099:, such as
3010:south node
2721:(e.g. the
2590:A type of
2585:cosmic ray
2546:space dust
2402:spacecraft
2279:proportion
2163:bolometric
2019:perihelion
1845:, and the
1815:axial tilt
1768:This is a
1716:hydrogen-1
1641:black hole
1623:barycenter
1515:barycenter
1499:barycenter
1471:true north
1428:plane and
1425:equatorial
1408:axial tilt
1340:precession
1321:atmosphere
1296:luminosity
1180:, and the
1000:and other
989:astrometry
964:A type of
878:exobiology
794:planetoids
788:meteoroids
676:parameters
643:north node
495:atmosphere
416:perihelion
322:black body
315:, that is
272:luminosity
249:black hole
147:References
17091:Astronomy
16895:Economics
16860:Chemistry
16835:Astronomy
16689:Telescope
16295:Spherical
16242:Gamma-ray
16211:(optical)
16016:Astronomy
15716:118784209
15691:1101.2156
15396:120268049
15204:119578058
15057:18293428M
14994:119059288
14960:(2): 11,
14694:122679154
14298:) of the
14056:Also the
13955:constants
13894:Also the
13767:periapsis
13542:satellite
13536:obliquity
13522:Milky Way
13484:satellite
13388:Milky Way
13309:from the
13257:telescope
13152:night sky
13118:solar day
12996: m/s
12974:or other
12941:'s final
12932:transient
12918:supernova
12863:cosmology
12807:and some
12731:astronomy
12691:starspots
12682:inside a
12468:telescope
12455:starfield
12280: m/s
12122:telescope
12063:longitude
12002:electrons
11953:solar day
11907:asteroids
11800:into the
11620:solar day
11555:solar day
11536:night sky
11523:astronomy
11410:solar day
11188:twinkling
11163:Milky Way
10866:longitude
10715:in their
10654:known as
10637:astronomy
10564:accretion
10393:protostar
10358:planetary
10139:planetoid
10046:asteroids
10013:around a
9937:red giant
9841:planetary
9835:exoplanet
9536:periapsis
9480:arcsecond
9351:periapsis
9336:around a
8914:around a
8811:Also the
8696:asteroids
8649:obliquity
8456:nighttime
8443:night sky
8317:from the
8210:naked eye
8124:neutrinos
8113:origins:
8098:astronomy
7899:night sky
7653:night sky
7628:Milky Way
7620:magnitude
7588:meteoroid
7558:meteorite
7512:night sky
7490:meteorite
7476:meteoroid
7460:meteorite
7424:meteoroid
7263:periapsis
7191:Also the
7114:naked eye
7097:magnitude
6968:full moon
6792:periapsis
6671:libration
6652:Local SCI
6642:Also the
6523:from the
6496:asteroids
6448:hyperbola
6317:isochrone
6287:eccentric
6119:astronomy
6089:cosmology
6024:volatiles
6005:(such as
5986:ice giant
5972:Andromeda
5967:Milky Way
5898:. On the
5875:geocenter
5732:Also the
5712:red giant
5694:evolution
5473:known as
5471:spacetime
5396:satellite
5213:celestial
5169:geocenter
5119:geocenter
5081:gas giant
5067:hypernova
5061:supernova
5050:gamma ray
5035:gamma-ray
5024:astronomy
4995:in 1610:
4885:Milky Way
4873:irregular
4809:Milky Way
4761:Milky Way
4729:Milky Way
4702:within a
4596:Ophiuchus
4565:Milky Way
4495:Milky Way
4449:waves to
4388:night sky
4321:upon the
4260:upon the
4246:Also the
4211:telescope
4073:exoplanet
4012:Milky Way
3938:evolution
3843:longitude
3768:onto the
3648:ephemeris
3492:and many
3432:equinoxes
3274:known as
3262:known as
3172:night sky
3102:cubewanos
3071:class of
3068:dynamical
3008:Also the
2988:evolution
2973:, e.g. a
2938:night sky
2635:cosmology
2615:cosmogony
2592:radiation
2524:eruption.
2434:mythology
2274:are in a
2248:volatiles
2224:frequency
2055:asteroids
1877:astronomy
1732:deuterium
1416:obliquity
1400:night sky
1286:chemistry
1258:phenomena
1244:astronomy
1198:astrology
1189:equinoxes
1183:solstices
863:main belt
848:asteroids
732:night sky
641:Also the
591:periapsis
538:periapsis
440:periapsis
55:Contents
40:cosmology
36:astronomy
17065:Virology
17050:Robotics
17015:Mycology
17005:Medicine
16850:Calculus
16739:Category
16448:Category
16343:Egyptian
16260:Neutrino
16195:Infrared
16143:Galactic
16118:Sidewalk
16072:Glossary
16042:Timeline
15853:15648424
15800:17029463
15595:Galaxies
14625:14732824
14341:See also
14301:ecliptic
14144:and the
13972:causally
13926:galaxies
13910:universe
13843:twilight
13824:and its
13786:and the
13679:meridian
13572:asteroid
13443:prograde
13243:observer
13232:velocity
13083:sunrises
13020:with an
12926:luminous
12409:galaxies
12324:hydrogen
12302:spheroid
12127:spectrum
12043:solstice
11959:meridian
11904:such as
11818:☉
11761:10
11740:☉
11587:meridian
11484:meridian
10956:coalesce
10893:moonlets
10747:prograde
10724:redshift
10355:A large
9806:orbiting
9744:such as
9689:such as
9679:such as
9614:aphelion
9560:apoapsis
9500:parallax
9475:parallax
9450:parallax
9429:Universe
9237:orbiting
9209:ecliptic
9115:and the
9106:inclined
8644:O and B.
8608:observed
8568:nutation
8533:prograde
8516:coplanar
8514:that is
8474:such as
8416:neutrons
8392:neutrino
8384:galaxies
8359:hydrogen
8298:asteroid
8218:bare eye
8153:N galaxy
7986:moonmoon
7539:hydrogen
7442:asteroid
7351:meridian
7317:meridian
6972:new moon
6823:(☊ or Ω)
6801:) of an
6798:apoapsis
6795:and the
6738:galactic
6688:far side
6508:centaurs
6493:such as
6444:parabola
6435:orbiting
6391:and the
6281:inclined
6196:redshift
6171:hydrogen
6130:infrared
6015:nitrogen
5999:hydrogen
5869:meridian
5828:and the
5809:meridian
5572:spheroid
5498:Big Bang
5260:circular
5094:hydrogen
5009:Callisto
5005:Ganymede
4950:galaxies
4901:galaxies
4600:Scorpius
4057:galaxies
3993:observer
3991:and the
3880:solstice
3861:March 20
3852:and the
3579:with an
3327:ecliptic
3111:objects.
2956:galaxies
2941:such as
2898:Be stars
2858:latitude
2779:, and a
2754:meridian
2647:Universe
2623:universe
2446:asterism
2360:, or to
2276:rational
2153:calcium
2136:, where
1928:meridian
1854:ecliptic
1821:ecliptic
1581:Big Bang
1475:altitude
1384:nutation
1371:and the
1194:almanacs
1172:zodiacal
1052:asteroid
954:objects.
746:asteroid
718:asterism
579:orbiting
544:apoapsis
425:apoapsis
401:aphelion
142:See also
17030:Physics
16980:Geology
16890:Ecology
16840:Biology
16795:science
16751:Commons
16703:history
16673:Russian
16521:Related
16430:Optical
16415:Tibetan
16399:Serbian
16392:Persian
16336:Chinese
16313:Culture
16233:History
16104:Amateur
16035:History
16028:Outline
15833:Bibcode
15780:Bibcode
15696:Bibcode
15447:Bibcode
15374:Bibcode
15347:Bibcode
15223:Bibcode
15184:Bibcode
15079:Bibcode
15013:Bibcode
14972:Bibcode
14927:Bibcode
14890:Bibcode
14888:: 618,
14672:Bibcode
14603:Bibcode
14529:Bibcode
14487:Bibcode
13938:planets
13720:eclipse
13665:transit
13490:primary
13366:models.
13279:of the
13163:Jupiter
13149:in the
13103:due to
13072:primary
13017:primary
12868:Ptolemy
12850:planets
12779:substar
12757:natural
12626:system.
12562:spectra
12493:stellar
12421:planets
12310:gravity
12133:as the
11998:protons
11938:of the
11892:, five
11889:planets
11673:annular
11667:partial
11639:of the
11463:of the
11441:of the
11297:ellipse
11224:secular
11217:horizon
11042:opacity
10914:around
10858:In the
10811:primary
10769:primary
10764:in situ
10530:shadow.
10508:or the
10410:For an
10286:primary
10236:primary
10216:Mercury
10185:equator
10081:planemo
10028:planets
10004:stellar
9972:planets
9827:of all
9815:gravity
9811:rounded
9695:Jupiter
9646:of the
9637:orbital
9631:primary
9569:perigee
9553:primary
9383:if all
9380:primary
9296:secular
9285:Neptune
9199:primary
9037:(grey).
8965:primary
8861:occurs.
8852:opacity
8714:primary
8483:planets
8466:horizon
8323:at its
8202:horizon
8082:cluster
8039:azimuth
7923:moonlet
7799:moonlet
7697:of the
7506:meteors
7345:transit
7016:(MACHO)
6786:apsides
6747:is the
6573:L-point
6502:trojans
6440:ellipse
6310:in situ
6299:primary
6241:orbital
6214:or the
6094:Ptolemy
6071:Mercury
6035:in the
6033:Neptune
5954:(often
5812:to the
5763:horizon
5655:versus
5533:photons
5274:in the
5271:equator
5148:of the
5108:in the
5102:Jupiter
4989:Jupiter
4806:of the
4670:quasars
4562:of the
4525:of the
4472:planets
4385:in the
3954:Sample
3819:equator
3811:equinox
3803:equinox
3765:equator
3711:equator
3665:in the
3599:ellipse
3489:planets
3419:equator
3254:Antares
3242:evolved
3202:system.
3091:Neptune
2950:nebulae
2850:In the
2776:horizon
2644:of the
2626:or the
2596:protons
2287:Jupiter
2005:centaur
1905:natural
1899:planets
1882:motions
1803:equator
1574:baryons
1534:of the
1509:systems
1464:azimuth
1442:seasons
1397:in the
1300:density
1282:physics
1227:of the
1157:of the
1154:planets
837:Jupiter
825:in the
771:Jupiter
588:to its
582:body's
532:primary
517:In the
502:appulse
470:perigee
433:primary
373:Am star
215:parsecs
172:In the
16845:Botany
16719:Zodiac
16659:French
16364:Indian
16357:Hebrew
16096:Manner
15876:
15851:
15798:
15743:
15718:, A27.
15714:
15684:: 16,
15659:
15632:
15574:
15547:
15519:, NASA
15496:, NASA
15474:
15419:
15394:
15320:
15293:
15267:
15202:
15106:
15055:
15045:
14992:
14776:
14739:
14692:
14646:
14623:
14566:
14460:
14433:
14403:
14281:zodiac
14252:(ZAMS)
14234:zenith
14208:X-rays
14183:galaxy
13959:entire
13947:energy
13943:matter
13861:, and
13728:trojan
13611:, and
13584:planet
13516:galaxy
13346:planet
13210:syzygy
13196:aspect
13190:planet
12977:object
12910:galaxy
12885:(SMBH)
12855:Saturn
12793:fusion
12680:plasma
12449:merger
12443:galaxy
12427:comets
12328:helium
12306:plasma
12284:32.174
12035:comets
12023:aurora
12017:corona
12004:, and
11916:, and
11913:comets
11803:corona
11708:facula
11547:(SSSB)
11344:zenith
11242:, the
11149:galaxy
11109:RS CVn
11033:of an
10981:, and
10905:planet
10792:réseau
10583:X-rays
10555:. Its
10536:quasar
10427:pulsar
10370:planet
10103:planet
10061:, and
9981:, and
9943:planet
9889:planet
9883:planet
9848:planet
9793:planet
9768:, and
9756:. The
9590:apogee
9580:or an
9504:second
9466:parsec
9457:parsec
9333:orbits
9246:(e.g.
9202:. The
9190:of an
9091:of an
9025:. The
8911:planet
8905:object
8785:object
8702:comets
8610:minus
8363:helium
8334:nebula
8263:planet
8257:orbits
8196:zenith
8167:Quasar
8127:, and
7950:planet
7911:phases
7758:planet
7694:center
7641:galaxy
7543:helium
7468:meteor
7403:meteor
7385:comets
7357:zenith
7331:zenith
7257:period
7208:zenith
7083:planet
6983:waning
6977:waxing
6891:joules
6876:galaxy
6750:parsec
6582:bodies
6505:, and
6175:helium
6166:galaxy
6155:matter
6029:Uranus
6019:sulfur
6017:, and
6011:carbon
6007:oxygen
6003:helium
5964:. The
5945:galaxy
5831:zenith
5775:zenith
5721:stars.
5715:, and
5688:tracks
5624:plasma
5521:nebula
5350:planet
5234:, etc.
5175:zenith
5106:Saturn
5098:helium
5007:, and
5001:Europa
4867:spiral
4846:, and
4817:galaxy
4781:galaxy
4755:galaxy
4705:galaxy
4646:galaxy
4598:, and
4570:galaxy
4559:center
4544:Auriga
4522:center
4500:galaxy
4451:X-rays
4279:Pisces
4171:galaxy
4119:facula
4082:planet
4017:galaxy
3719:planet
3693:of an
3640:planet
3594:energy
3545:spiral
3535:galaxy
3425:tilted
3154:planet
3083:whose
2953:, and
2736:planet
2727:, the
2628:cosmos
2509:corona
2498:plasma
2462:plasma
2455:corona
2354:, and
2283:Saturn
2084:galaxy
2061:comets
1902:, and
1860:tilted
1837:, its
1657:blazar
1559:planet
1306:, and
1169:, the
1163:, the
1132:galaxy
1126:nebula
1040:planet
782:comets
698:planet
691:aspect
460:or an
449:apogee
365:albedo
312:planet
294:albedo
266:galaxy
16710:lists
16680:Women
16371:Inuit
16350:Greek
16288:Radar
16226:X-ray
16181:Radio
16161:Solar
15849:S2CID
15823:arXiv
15796:S2CID
15770:arXiv
15712:S2CID
15686:arXiv
15392:S2CID
15200:S2CID
15130:, GNU
14996:, 227
14990:S2CID
14962:arXiv
14917:arXiv
14690:S2CID
14621:S2CID
14593:arXiv
14517:(PDF)
14265:stars
14167:XBONG
13932:stars
13917:space
13858:civil
13818:of a
13778:focus
13756:, or
13657:(TNO)
13578:comet
13561:Also
13510:stars
13420:Also
13049:Also
13011:orbit
12992:9.806
12777:Also
12556:stars
12545:Also
12520:Also
12483:Rigel
12462:stars
12447:as a
12391:stars
12380:Also
12326:into
12276:9.806
12254:Also
12185:Also
11843:stars
11769:stars
11754:1.988
11670:, or
11661:total
11508:Earth
11327:Also
11287:Also
11186:Also
10969:Also
10839:In a
10624:star.
10577:from
10542:Also
10275:Also
10250:, or
10242:Also
10174:poles
10169:orbit
10079:Also
10074:(PMO)
10040:moons
10010:orbit
9978:moons
9862:Also
9736:plane
9726:Also
9681:Venus
9542:Also
9406:space
9328:speed
9281:Pluto
9187:orbit
9155:orbit
9138:Also
9094:orbit
9088:plane
9051:orbit
9007:orbit
8985:orbit
8959:orbit
8948:Also
8920:or a
8893:orbit
8797:lunar
8791:Solar
8708:orbit
8673:Also
8635:stars
8549:(NSC)
8542:ones.
8511:orbit
8477:stars
8435:(NGC)
8309:Earth
8304:comet
8285:(NEO)
8254:that
8240:Also
8216:Also
8205:line.
8182:nadir
8070:stars
8059:Also
8042:of a
8028:Also
8010:Also
7929:Also
7916:lunar
7887:tides
7842:Also
7764:comet
7746:orbit
7659:stars
7565:to 2
7524:orbit
7518:comet
7439:, or
7436:comet
7409:Also
7129:stars
6934:Also
6913:lunar
6895:watts
6885:. In
6836:orbit
6789:(the
6693:limbs
6650:, or
6588:orbit
6571:, or
6563:Also
6543:Pluto
6473:Also
6446:, or
6424:Also
6388:epoch
6228:of a
6210:Also
6163:in a
6160:stars
6149:(ISM)
6139:(IAU)
6075:Venus
5820:plane
5770:plane
5664:stars
5393:as a
5384:orbit
5378:stars
5297:(GSO)
5245:Also
5150:Earth
5044:(GRB)
4984:moons
4939:Also
4870:, or
4825:stars
4752:of a
4711:orbit
4684:Also
4631:Also
4447:radio
4445:from
4400:stars
4371:Also
4340:Virgo
4071:Also
4051:stars
3910:orbit
3780:), a
3724:plane
3676:epoch
3565:Also
3474:), a
3347:plane
3333:Also
3248:like
3192:stars
3053:Also
2979:or a
2907:(DSO)
2707:Also
2666:Also
2573:Also
2568:(CMB)
2544:Also
2492:(CME)
2328:Also
2235:comet
2093:or a
2077:(CMO)
2022:or a
1893:stars
1776:of a
1739:bulge
1670:Also
1617:stars
1527:orbit
1414:Also
1327:star.
1129:, or
1091:Also
1049:, or
1017:Also
997:stars
945:Also
887:space
876:Also
726:stars
613:orbit
564:Also
523:of a
520:orbit
512:apsis
485:Also
282:stars
259:(AGN)
237:orbit
30:This
16797:and
16441:List
16406:folk
16378:Maya
15874:ISBN
15741:ISBN
15657:ISBN
15630:ISBN
15572:ISBN
15545:ISBN
15472:ISBN
15417:ISBN
15318:ISBN
15291:ISBN
15265:ISBN
15162:2020
15136:2020
15104:ISBN
15043:ISBN
14774:ISBN
14737:ISBN
14644:ISBN
14564:ISBN
14458:ISBN
14431:ISBN
14401:ISBN
14319:Moon
14126:and
14123:nova
14024:The
14000:star
13997:Any
13953:and
13945:and
13921:time
13919:and
13496:Moon
13403:and
13352:star
13340:moon
13272:star
13109:and
13088:star
13060:axis
13008:Any
12964:The
12938:star
12754:Any
12694:and
12685:star
12531:star
12500:star
12481:and
12440:Any
12406:and
12295:star
12095:See
11856:See
11785:loop
11648:Moon
11618:mean
11514:and
11423:The
11377:The
11263:Moon
11203:star
11111:and
11004:star
10989:Any
10951:ring
10890:and
10887:dust
10668:Any
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10116:and
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