Variable star - Knowledge

1277: 318: 2022: 1629: 886: 5661: 32: 5711: 1875: 5735: 590: 5699: 5723: 129: 5672: 4140: 1088:

be long-term variations over periods of several years. Their spectra are of type F or G at maximum light and type K or M at minimum brightness. They lie near the instability strip, cooler than type I Cepheids more luminous than type II Cepheids. Their pulsations are caused by the same basic mechanisms related to helium opacity, but they are at a very different stage of their lives.

1393:. They have permanent high mass loss, but at intervals of years internal pulsations cause the star to exceed its Eddington limit and the mass loss increases hugely. Visual brightness increases although the overall luminosity is largely unchanged. Giant eruptions observed in a few LBVs do increase the luminosity, so much so that they have been tagged 455:

contract. As the gas is thereby compressed, it is heated and the degree of ionization again increases. This makes the gas more opaque, and radiation temporarily becomes captured in the gas. This heats the gas further, leading it to expand once again. Thus a cycle of expansion and compression (swelling and shrinking) is maintained.

1766:

the white dwarf, but its innermost regions are magnetically truncated by the white dwarf. Once captured by the white dwarf's magnetic field, the material from the inner disk travels along the magnetic field lines until it accretes. In extreme cases, the white dwarf's magnetism prevents the formation of an accretion disk.

1765:

DQ Herculis systems are interacting binaries in which a low-mass star transfers mass to a highly magnetic white dwarf. The white dwarf spin period is significantly shorter than the binary orbital period and can sometimes be detected as a photometric periodicity. An accretion disk usually forms around

1835:

may show significant variations in brightness as they rotate, and brighter areas of the surface are brought into view. Bright spots also occur at the magnetic poles of magnetic stars. Stars with ellipsoidal shapes may also show changes in brightness as they present varying areas of their surfaces to

1603:

Supernovae can result from the death of an extremely massive star, many times heavier than the Sun. At the end of the life of this massive star, a non-fusible iron core is formed from fusion ashes. This iron core is pushed towards the Chandrasekhar limit till it surpasses it and therefore collapses.

1430:

While classed as eruptive variables, these stars do not undergo periodic increases in brightness. Instead they spend most of their time at maximum brightness, but at irregular intervals they suddenly fade by 1–9 magnitudes (2.5 to 4000 times dimmer) before recovering to their initial brightness over

1087:

These are yellow supergiant stars (actually low mass post-AGB stars at the most luminous stage of their lives) which have alternating deep and shallow minima. This double-peaked variation typically has periods of 30–100 days and amplitudes of 3–4 magnitudes. Superimposed on this variation, there may

454:

When the star is in the swelling phase, its outer layers expand, causing them to cool. Because of the decreasing temperature the degree of ionization also decreases. This makes the gas more transparent, and thus makes it easier for the star to radiate its energy. This in turn makes the star start to

1574:, causing the object to collapse in a fraction of a second. This collapse "bounces" and causes the star to explode and emit this enormous energy quantity. The outer layers of these stars are blown away at speeds of many thousands of kilometers per second. The expelled matter may form nebulae called 983:

Many variable red giants and supergiants show variations over several hundred to several thousand days. The brightness may change by several magnitudes although it is often much smaller, with the more rapid primary variations are superimposed. The reasons for this type of variation are not clearly

1780:

In these cataclysmic variables, the white dwarf's magnetic field is so strong that it synchronizes the white dwarf's spin period with the binary orbital period. Instead of forming an accretion disk, the accretion flow is channeled along the white dwarf's magnetic field lines until it impacts the

920:

itself, also known as Omicron Ceti (ο Cet), varies in brightness from almost 2nd magnitude to as faint as 10th magnitude with a period of roughly 332 days. The very large visual amplitudes are mainly due to the shifting of energy output between visual and infra-red as the temperature of the star

2115:

W Serpentis is the prototype of a class of semi-detached binaries including a giant or supergiant transferring material to a massive more compact star. They are characterised, and distinguished from the similar β Lyr systems, by strong UV emission from accretions hotspots on a disc of material.

1411:

These massive evolved stars are unstable due to their high luminosity and position above the instability strip, and they exhibit slow but sometimes large photometric and spectroscopic changes due to high mass loss and occasional larger eruptions, combined with secular variation on an observable

653:

The expansion phase of a pulsation is caused by the blocking of the internal energy flow by material with a high opacity, but this must occur at a particular depth of the star to create visible pulsations. If the expansion occurs below a convective zone then no variation will be visible at the

654:

surface. If the expansion occurs too close to the surface the restoring force will be too weak to create a pulsation. The restoring force to create the contraction phase of a pulsation can be pressure if the pulsation occurs in a non-degenerate layer deep inside a star, and this is called an

442:

Combining light curves with spectral data often gives a clue as to the changes that occur in a variable star. For example, evidence for a pulsating star is found in its shifting spectrum because its surface periodically moves toward and away from us, with the same frequency as its changing

1513:

variables, very faint main-sequence stars which undergo regular flares. They increase in brightness by up to two magnitudes (six times brighter) in just a few seconds, and then fade back to normal brightness in half an hour or less. Several nearby red dwarfs are flare stars, including

1002:

variables, especially in Europe) undergo short period pulsations in the order of 0.1–0.6 days with an amplitude of 0.01–0.3 magnitudes (1% to 30% change in luminosity). They are at their brightest during minimum contraction. Many stars of this kind exhibits multiple pulsation periods.

1536:

These are close binary systems with highly active chromospheres, including huge sunspots and flares, believed to be enhanced by the close companion. Variability scales ranges from days, close to the orbital period and sometimes also with eclipses, to years as sunspot activity varies.

1619:

from a star companion in a double star system. The Chandrasekhar limit is surpassed from the infalling matter. The absolute luminosity of this latter type is related to properties of its light curve, so that these supernovae can be used to establish the distance to other galaxies.

1240:

A fast yellow pulsating supergiant (FYPS) is a luminous yellow supergiant with pulsations shorter than a day. They are thought to have evolved beyond a red supergiant phase, but the mechanism for the pulsations is unknown. The class was named in 2020 through analysis of

450:

showed that the mathematical equations that describe the interior of a star may lead to instabilities that cause a star to pulsate. The most common type of instability is related to oscillations in the degree of ionization in outer, convective layers of the star.

1814:

AM CVn variables are symbiotic binaries where a white dwarf is accreting helium-rich material from either another white dwarf, a helium star, or an evolved main-sequence star. They undergo complex variations, or at times no variations, with ultrashort periods.

1114:

Ia. Their periods range from several days to several weeks, and their amplitudes of variation are typically of the order of 0.1 magnitudes. The light changes, which often seem irregular, are caused by the superposition of many oscillations with close periods.

637:

which is a higher frequency, corresponding to a shorter period. Pulsating variable stars sometimes have a single well-defined period, but often they pulsate simultaneously with multiple frequencies and complex analysis is required to determine the separate

811:. They also have a well established period-luminosity relationship, and so are also useful as distance indicators. These A-type stars vary by about 0.2–2 magnitudes (20% to over 500% change in luminosity) over a period of several hours to a day or more. 1343:

These stars reside in reflection nebulae and show gradual increases in their luminosity in the order of 6 magnitudes followed by a lengthy phase of constant brightness. They then dim by 2 magnitudes (six times dimmer) or so over a period of many years.

776:

Type II Cepheids (historically termed W Virginis stars) have extremely regular light pulsations and a luminosity relation much like the δ Cephei variables, so initially they were confused with the latter category. Type II Cepheids stars belong to older

1849:

These are very close binaries, the components of which are non-spherical due to their tidal interaction. As the stars rotate the area of their surface presented towards the observer changes and this in turn affects their brightness as seen from Earth.

1666:

are also the result of dramatic explosions, but unlike supernovae do not result in the destruction of the progenitor star. Also unlike supernovae, novae ignite from the sudden onset of thermonuclear fusion, which under certain high pressure conditions

566:

Rotating variables, stars whose variability is caused by phenomena related to their rotation. Examples are stars with extreme "sunspots" which affect the apparent brightness or stars that have fast rotation speeds causing them to become ellipsoidal in

1453:

Classic population I Wolf–Rayet stars are massive hot stars that sometimes show variability, probably due to several different causes including binary interactions and rotating gas clumps around the star. They exhibit broad emission line spectra with

829:. They often show many superimposed periods, which combine to form an extremely complex light curve. The typical δ Scuti star has an amplitude of 0.003–0.9 magnitudes (0.3% to about 130% change in luminosity) and a period of 0.01–0.2 days. Their 947:, which varies from about magnitudes +0.2 to +1.2 (a factor 2.5 change in luminosity). At least some of the semi-regular variables are very closely related to Mira variables, possibly the only difference being pulsating in a different harmonic. 847:

These stars of spectral type A2 to F5, similar to δ Scuti variables, are found mainly in globular clusters. They exhibit fluctuations in their brightness in the order of 0.7 magnitude (about 100% change in luminosity) or so every 1 to 2 hours.

2142:

may also show brightness variations if their planets pass between Earth and the star. These variations are much smaller than those seen with stellar companions and are only detectable with extremely accurate observations. Examples include

356:

can be very well established; for many variable stars, though, these quantities may vary slowly over time, or even from one period to the next. Peak brightnesses in the light curve are known as maxima, while troughs are known as minima.

2033:

Extrinsic variables have variations in their brightness, as seen by terrestrial observers, due to some external source. One of the most common reasons for this is the presence of a binary companion star, so that the two together form a

500:. Later discoveries used letters AA through AZ, BB through BZ, and up to QQ through QZ (with J omitted). Once those 334 combinations are exhausted, variables are numbered in order of discovery, starting with the prefixed V335 onwards. 862:

These stars of spectral type A or occasionally F0, a sub-class of δ Scuti variables found on the main sequence. They have extremely rapid variations with periods of a few minutes and amplitudes of a few thousandths of a magnitude.

1795:

These symbiotic binary systems are composed of a red giant and a hot blue star enveloped in a cloud of gas and dust. They undergo nova-like outbursts with amplitudes of up to 4 magnitudes. The prototype for this class is

745:

Classical Cepheids (or Delta Cephei variables) are population I (young, massive, and luminous) yellow supergiants which undergo pulsations with very regular periods on the order of days to months. On September 10, 1784,

943:. Semiregular variables may show a definite period on occasion, but more often show less well-defined variations that can sometimes be resolved into multiple periods. A well-known example of a semiregular variable is 1253:

Eruptive variable stars show irregular or semi-regular brightness variations caused by material being lost from the star, or in some cases being accreted to it. Despite the name, these are not explosive events.

1155:

These non-radially pulsating stars have short periods of hundreds to thousands of seconds with tiny fluctuations of 0.001 to 0.2 magnitudes. Known types of pulsating white dwarf (or pre-white dwarf) include the

1487:(γ Cas) variables are non-supergiant fast-rotating B class emission line-type stars that fluctuate irregularly by up to 1.5 magnitudes (4 fold change in luminosity) due to the ejection of matter at their 1720:, which have outbursts lasting roughly 5–20 days followed by quiet periods of typically a few hundred days. During an outburst they brighten typically by 2–6 magnitudes. These stars are also known as 1039:. They pulsate with periods of a few minutes and may simultaneous pulsate with multiple periods. They have amplitudes of a few hundredths of a magnitude and are given the GCVS acronym RPHS. They are 2331:

Jetsu, L.; Porceddu, S.; Lyytinen, J.; Kajatkari, P.; Lehtinen, J.; Markkanen, T.; et al. (2013). "Did the Ancient Egyptians Record the Period of the Eclipsing Binary Algol - The Raging One?".

1570:, brightening by more than 20 magnitudes (over one hundred million times brighter). The supernova explosion is caused by a white dwarf or a star core reaching a certain mass/density limit, the 1350:

for example dimmed by 2.5 magnitude (ten times dimmer) during an eleven-year period. FU Orionis variables are of spectral type A through G and are possibly an evolutionary phase in the life of

201:

An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago may be the oldest preserved historical document of the discovery of a variable star, the eclipsing binary

2003:

change in brightness as they rotate. Because of the rapid rotation, brightness variations are extremely fast, from milliseconds to a few seconds. The first and the best known example is the

708:

between period and absolute magnitude, as well as a relation between period and mean density of the star. The period-luminosity relationship was first established for Delta Cepheids by

1675:, one component being a white dwarf accreting matter from the other ordinary star component, and may recur over periods of decades to centuries or millennia. Novae are categorised as 420:

if the wavelengths of spectral lines are shifted this points to movements (for example, a periodical swelling and shrinking of the star, or its rotation, or an expanding gas shell) (

240:

and other ancient philosophers had taught. In this way, the discovery of variable stars contributed to the astronomical revolution of the sixteenth and early seventeenth centuries.

160:) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: 1268:

Protostars are young objects that have not yet completed the process of contraction from a gas nebula to a veritable star. Most protostars exhibit irregular brightness variations.

367:

field of view of which the magnitudes are known and constant. By estimating the variable's magnitude and noting the time of observation a visual lightcurve can be constructed. The

785:, much lower mass, somewhat lower luminosity, and a slightly offset period versus luminosity relationship, so it is always important to know which type of star is being observed. 5512: 921:

changes. In a few cases, Mira variables show dramatic period changes over a period of decades, thought to be related to the thermal pulsing cycle of the most advanced AGB stars.

1566:

Supernovae are the most dramatic type of cataclysmic variable, being some of the most energetic events in the universe. A supernova can briefly emit as much energy as an entire

1214:

is used to describe oscillations in other stars that are excited in the same way and the study of these oscillations is one of the main areas of active research in the field of

417:

changes in brightness may depend strongly on the part of the spectrum that is observed (for example, large variations in visible light but hardly any changes in the infrared)

573:

These subgroups themselves are further divided into specific types of variable stars that are usually named after their prototype. For example, dwarf novae are designated

275:. Since 1850, the number of known variable stars has increased rapidly, especially after 1890 when it became possible to identify variable stars by means of photography. 1431:

months to years. Most are classified as yellow supergiants by luminosity, although they are actually post-AGB stars, but there are both red and blue giant R CrB stars.

2130:

The stars in this group show periods of less than a day. The stars are so closely situated to each other that their surfaces are almost in contact with each other.

2734: 2107:. The light curves of this class of eclipsing variables are constantly changing, making it almost impossible to determine the exact onset and end of each eclipse. 2636: 2085:

Double periodic variables exhibit cyclical mass exchange which causes the orbital period to vary predictably over a very long period. The best known example is

523:: stars where the variability is being caused by changes in the physical properties of the stars themselves. This category can be divided into three subgroups. 1057:

Stars in this class are type Bp supergiants with a period of 0.1–1 day and an amplitude of 0.1 magnitude on average. Their spectra are peculiar by having weak

1276: 1588:

and elsewhere in 1054. The progenitor object may either disintegrate completely in the explosion, or, in the case of a massive star, the core can become a

1364:

Large stars lose their matter relatively easily. For this reason variability due to eruptions and mass loss is fairly common among giants and supergiants.

286:. Her analyses and observations of variable stars, carried out with her husband, Sergei Gaposchkin, laid the basis for all subsequent work on the subject. 2709: 1017:

Slowly pulsating B (SPB) stars are hot main-sequence stars slightly less luminous than the Beta Cephei stars, with longer periods and larger amplitudes.

969:

with little or no detectable periodicity. Some are poorly studied semiregular variables, often with multiple periods, but others may simply be chaotic.

384:

what is the shape of the light curve (symmetrical or not, angular or smoothly varying, does each cycle have only one or more than one minima, etcetera)?

1232:

A Blue Large-Amplitude Pulsator (BLAP) is a pulsating star characterized by changes of 0.2 to 0.4 magnitudes with typical periods of 20 to 40 minutes.

1321:

usually embedded in nebulosity. They have irregular periods with amplitudes of several magnitudes. A well-known subtype of Orion variables are the

1977:

Stars in this class exhibit brightness fluctuations of some 0.1 magnitude caused by changes in their magnetic fields due to high rotation speeds.

799:

These stars are somewhat similar to Cepheids, but are not as luminous and have shorter periods. They are older than type I Cepheids, belonging to

704:

mechanism for pulsating variables is believed to account for cepheid-like pulsations. Each of the subgroups on the instability strip has a fixed

368: 3606: 2086: 1283: 140:

taken in January 2019 and December 2019, showing the changes in brightness and shape. Betelgeuse is an intrinsically variable star.

301:

The most common kinds of variability involve changes in brightness, but other types of variability also occur, in particular changes in the

2895:

Messina, Sergio (2007). "Evidence for the pulsational origin of the Long Secondary Periods: The red supergiant star V424 Lac (HD 216946)".

1781:

white dwarf near a magnetic pole. Cyclotron radiation beamed from the accretion region can cause orbital variations of several magnitudes.

1202:

oscillates with very low amplitude in a large number of modes having periods around 5 minutes. The study of these oscillations is known as

619: 293:(2008) lists more than 46,000 variable stars in the Milky Way, as well as 10,000 in other galaxies, and over 10,000 'suspected' variables. 282:

published the book The Stars of High Luminosity, in which she made numerous observations of variable stars, paying particular attention to

173:, whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star 2685: 1919: 411:

is it a single star, or a binary? (the combined spectrum of a binary star may show elements from the spectra of each of the member stars)

3336:

Dorn-Wallenstein, Trevor Z.; Levesque, Emily M.; Neugent, Kathryn F.; Davenport, James R. A.; Morris, Brett M.; Gootkin, Keyan (2020).

2060:

Algol variables undergo eclipses with one or two minima separated by periods of nearly constant light. The prototype of this class is

1963:

stars of spectral class B8–A7 that show fluctuations of 0.01 to 0.1 magnitudes (1% to 10%) due to changes in their magnetic fields.

526:

Pulsating variables, stars whose radius alternately expands and contracts as part of their natural evolutionary ageing processes.

825:

Delta Scuti (δ Sct) variables are similar to Cepheids but much fainter and with much shorter periods. They were once known as

5544: 3283:

Nagel, T.; Werner, K. (2004). "Detection of non-radial g-mode pulsations in the newly discovered PG 1159 star HE 1429-1209".

3038: 2744: 2220: 1882: 1227: 754:, the first known representative of the class of Cepheid variables. However, the namesake for classical Cepheids is the star 978: 96: 3094:

De Cat, P. (2002). "An Observational Overview of Pulsations in β Cep Stars and Slowly Pulsating B Stars (invited paper)".

68: 290: 548:: stars where the variability is caused by external properties like rotation or eclipses. There are two main subgroups. 430:

abnormal emission or absorption lines may be indication of a hot stellar atmosphere, or gas clouds surrounding the star.

5519: 4838: 3599: 4078: 3226: 2644: 2578: 1954: 1775: 1713:

in which matter transfer between the component gives rise to regular outbursts. There are three types of dwarf nova:

115: 75: 877:

The long period variables are cool evolved stars that pulsate with periods in the range of weeks to several years.

642:

periods. In some cases, the pulsations do not have a defined frequency, causing a random variation, referred to as

5231: 1922:. A possible explanation for the rapid rotation of FK Comae stars is that they are the result of the merger of a 639: 594: 485: 434:

In very few cases it is possible to make pictures of a stellar disk. These may show darker spots on its surface.

371:

collects such observations from participants around the world and shares the data with the scientific community.

363:

can do useful scientific study of variable stars by visually comparing the star with other stars within the same

1940:

BY Draconis stars are of spectral class K or M and vary by less than 0.5 magnitudes (70% change in luminosity).

1866:

too may vary in brightness. As the star rotates we observe brightness variations of a few tenths of magnitudes.

1645:

Luminous red novae are stellar explosions caused by the merger of two stars. They are not related to classical

614:

Pulsating stars swell and shrink, affecting their brightness and spectrum. Pulsations are generally split into:

5765: 5524: 5161: 5145: 4180: 492:, who gave the first previously unnamed variable in a constellation the letter R, the first letter not used by 82: 53: 49: 309:

data with observed spectral changes, astronomers are often able to explain why a particular star is variable.

5571: 5438: 4041: 3896: 3727: 3592: 3163: 1531: 1141:

F to late A. Their periods are around one day and their amplitudes typically of the order of 0.1 magnitudes.

480:

In a given constellation, the first variable stars discovered were designated with letters R through Z, e.g.

228:(later named Mira) pulsated in a cycle taking 11 months; the star had previously been described as a nova by 5554: 5505: 5480: 4773: 3717: 1012: 563:'s vantage point the stars occasionally eclipse one another as they orbit, or the planet eclipses its star. 489: 221: 3338:"Short Term Variability of Evolved Massive Stars with TESS II: A New Class of Cool, Pulsating Supergiants" 64: 5495: 5475: 3858: 3684: 2200: 1425: 857: 4858: 2983:

Olivier, E. A.; Wood, P. R. (2003). "On the Origin of Long Secondary Periods in Semiregular Variables".

712:, and makes these high luminosity Cepheids very useful for determining distances to galaxies within the 5689: 5559: 5490: 5460: 4120: 3917: 3648: 2521: 2284:

Porceddu, S.; Jetsu, L.; Lyytinen, J.; Kajatkari, P.; Lehtinen, J.; Markkanen, T.; et al. (2008).

1479: 1318: 1263: 740: 705: 3244:"Mapping the Instability Domains of GW Vir Stars in the Effective Temperature-Surface Gravity Diagram" 217:, incorporating these brightness changes into narratives that are passed down through oral tradition. 5566: 5443: 5420: 5002: 4451: 4446: 4441: 4436: 4431: 4426: 3949: 3941: 3891: 3750: 3737: 3490:

Livio, Mario; Soker, Noam (June 1988). "The Common Envelope Phase in the Evolution of Binary Stars".

2386:"Shifting Milestones of Natural Sciences: The Ancient Egyptian Discovery of Algol's Period Confirmed" 1809: 1672: 1546: 1182:

stars, with atmospheres dominated by helium, carbon, and oxygen. GW Vir stars may be subdivided into

532:

Cataclysmic or explosive variables, stars that undergo a cataclysmic change in their properties like

475: 264: 3005: 4709: 4583: 4218: 4125: 3886: 2125: 2080: 1858:

The surface of the star is not uniformly bright, but has darker and brighter areas (like the sun's

1649:. They have a characteristic red appearance and very slow decline following the initial outburst. 1439:

are a subclass of R CrB variables that have a periodic variability in addition to their eruptions.

529:

Eruptive variables, stars who experience eruptions on their surfaces like flares or mass ejections.

447: 414:

does the spectrum change with time? (for example, the star may turn hotter and cooler periodically)

279: 167:, whose luminosity actually changes periodically; for example, because the star swells and shrinks. 3395: 5755: 5485: 5236: 5035: 4945: 4905: 4887: 4813: 4384: 4310: 3922: 3776: 3755: 2658:

Samus, N. N.; Kazarovets, E. V.; Durlevich, O. V. (2001). "General Catalogue of Variable Stars".

2068: 1550: 1329:

is due to spots on the stellar surface and gas-dust clumps, orbiting in the circumstellar disks.

1211: 956: 909: 42: 3419: 2611: 5646: 5626: 5398: 5393: 5291: 5186: 5135: 4940: 4930: 4603: 4401: 4369: 4260: 4243: 4149: 3853: 3806: 3802: 3771: 3722: 3000: 2174: 2164: 1725: 1609: 1373: 1132: 1120: 1052: 830: 709: 333: 206: 3530: 2454: 1505:

In main-sequence stars major eruptive variability is exceptional. It is common only among the

5500: 5470: 5465: 5455: 5383: 5171: 4337: 3997: 3781: 3689: 1790: 1741: 1731: 1150: 842: 697: 626: 4618: 4102: 3458: 3306: 3072: 2016: 1470:

lines. Variations in some stars appear to be stochastic while others show multiple periods.

5641: 5539: 5529: 5378: 5346: 5140: 4935: 4920: 4233: 4057: 3712: 3707: 3664: 3652: 3499: 3454: 3359: 3302: 3255: 3214: 3175: 3134: 3103: 3068: 2992: 2949: 2904: 2863: 2826: 2773: 2667: 2476: 2407: 2350: 2297: 2250: 2042:

the other, causing a reduction in brightness. One of the most famous eclipsing binaries is

1935: 1097: 1026: 993: 930: 912:(AGB) red giants. Over periods of many months they fade and brighten by between 2.5 and 11 872: 820: 625:

Depending on the type of pulsation and its location within the star, there is a natural or

89: 3059:

Lesh, J. R.; Aizenman, M. L. (1978). "The observational status of the Beta Cephei stars".

720:

used this method to prove that the so-called spiral nebulae are in fact distant galaxies.

8: 5760: 5739: 5101: 5084: 4755: 4657: 4480: 4115: 4088: 3927: 3668: 2098: 1972: 1887:

data; the inset, adapted from Panov and Dimitrov (2007), shows the long term variability.

1571: 1448: 1070: 496:. Letters RR through RZ, SS through SZ, up to ZZ are used for the next discoveries, e.g. 317: 244: 5241: 3503: 3363: 3259: 3218: 3179: 3138: 3107: 3080: 2996: 2953: 2908: 2867: 2830: 2777: 2671: 2480: 2411: 2354: 2301: 2254: 5727: 5715: 5636: 5597: 5549: 5534: 5448: 5388: 5311: 5221: 5191: 5181: 5125: 5047: 4738: 4374: 4173: 3975: 3863: 3472: 3377: 3349: 3318: 3292: 3191: 3018: 2965: 2939: 2789: 2595: 2551: 2533: 2502: 2466: 2430: 2397: 2385: 2366: 2340: 2313: 2266: 2212: 2169: 2026: 2021: 1911: 1760: 1436: 1432: 1394: 1300: 1290: 999: 913: 446:

About two-thirds of all variable stars appear to be pulsating. In the 1930s astronomer

174: 157: 2785: 2547: 1823:

There are two main groups of extrinsic variables: rotating stars and eclipsing stars.

236:

observed in 1572 and 1604, proved that the starry sky was not eternally invariable as

5587: 5012: 4985: 4965: 4765: 4549: 4537: 4364: 4344: 4298: 4280: 4248: 3959: 3870: 3814: 3679: 3672: 3623: 3476: 3381: 3222: 3195: 3187: 2851: 2814: 2793: 2761: 2740: 2574: 2555: 2506: 2435: 2370: 2317: 2216: 2179: 2139: 1721: 1668: 1640: 1576: 1484: 1406: 1280: 1082: 794: 689: 615: 609: 556: 493: 360: 337: 5072: 3022: 2612:"Cecilia Payne-Gaposchkin | British Astronomer & Harvard Professor | Britannica" 2362: 2270: 1881:

for FK Comae Berenices. The main plot shows the short term variability plotted from

1728:

which produces among the brightest and most frequent displays of this variable type.

1382:

variables, the most luminous stars known belong to this class. Examples include the

984:

understood, being variously ascribed to pulsations, binarity, and stellar rotation.

5703: 5415: 5368: 5318: 5306: 5284: 5279: 5206: 5166: 5113: 4895: 4818: 4793: 4687: 4608: 4332: 4293: 4015: 4002: 3632: 3579: 3542: 3507: 3462: 3367: 3322: 3310: 3263: 3183: 3142: 3076: 3036:

Variable Star Of The Season, Winter 2005: The Beta Cephei Stars and Their Relatives

3010: 2969: 2957: 2912: 2871: 2781: 2543: 2492: 2484: 2425: 2415: 2358: 2305: 2258: 2208: 1717: 1633: 1515: 1215: 1138: 804: 771: 683: 647: 459: 393: 302: 283: 3574: 3314: 3035: 2710:"OpenStax: Astronomy | 19.3 Variable Stars: One Key to Cosmic Distances | Top Hat" 1137:

Gamma Doradus (γ Dor) variables are non-radially pulsating main-sequence stars of

5602: 5405: 5274: 5118: 5089: 5030: 5025: 4900: 4628: 4593: 4527: 4473: 4468: 4413: 4223: 3825: 3659: 3467: 3442: 3042: 2916: 2420: 2286:"Evidence of Periodicity in Ancient Egyptian Calendars of Lucky and Unlucky Days" 2148: 1692: 1413: 1338: 1203: 1036: 256: 229: 2930:

Soszyński, I. (2007). "Long Secondary Periods and Binarity in Red Giant Stars".

2522:"Yes, Aboriginal Australians can and did discover the variability of Betelgeuse" 2103:

Beta Lyrae (β Lyr) variables are extremely close binaries, named after the star

5664: 5430: 5269: 5096: 5067: 5042: 4975: 4664: 4532: 4418: 4320: 4210: 4200: 4110: 4008: 3819: 3643: 3372: 3337: 2152: 2055: 1923: 1312: 1103: 966: 940: 759: 421: 378:

are the brightness variations periodical, semiperiodical, irregular, or unique?

248: 220:

Of the modern astronomers, the first variable star was identified in 1638 when

2330: 2309: 2283: 2262: 1303:

is thought to be due to gas-dust clumps, orbiting in the circumstellar disks.

701: 243:

The second variable star to be described was the eclipsing variable Algol, by

5749: 5616: 5410: 5373: 5341: 4925: 4748: 4719: 4697: 4315: 4288: 4265: 4166: 3745: 2600:. Osmania University, Digital Library Of India. McGraw Hill Book Company Inc. 2065: 1996: 1960: 1907: 1900: 1746: 1628: 903: 893: 803:, but of lower mass than type II Cepheids. Due to their common occurrence in 800: 778: 747: 326: 20: 3547: 267:. By 1786, ten variable stars were known. John Goodricke himself discovered 5676: 5351: 5301: 5296: 5196: 5079: 5062: 5020: 4990: 4980: 4915: 4798: 4743: 4724: 4704: 4682: 4674: 4517: 4510: 4349: 4270: 4253: 3969: 3832: 2439: 2000: 1904: 1863: 1797: 1589: 1352: 1326: 1322: 755: 724: 717: 671: 481: 341: 268: 225: 688:

This group consists of several kinds of pulsating stars, all found on the

5592: 5264: 5256: 5246: 5226: 5201: 5130: 5052: 4808: 4783: 4778: 4692: 4652: 4613: 4578: 4561: 4556: 4228: 4144: 3297: 2944: 2035: 2004: 1915: 1896: 1878: 1710: 1616: 1581: 1386: 1346: 1176:, stars, with helium-dominated atmospheres and the spectral type DB; and 1040: 1032: 889: 782: 751: 728: 713: 674:. Pulsating variable stars typically pulsate in only one of these modes. 663: 552: 345: 322: 306: 190: 182: 3335: 2497: 885: 344:. Measurements of their changes in brightness can be plotted to produce 5176: 4873: 4846: 4823: 4803: 4788: 4640: 4544: 4522: 4500: 4495: 4359: 3954: 3912: 3147: 3122: 2488: 2104: 1750:. These binary systems usually have orbital periods of under 2.5 hours. 1704: 1597: 1506: 1500: 1383: 1207: 1166:, stars, with hydrogen-dominated atmospheres and the spectral type DA; 1102:

Alpha Cygni (α Cyg) variables are nonradially pulsating supergiants of

962: 944: 936: 643: 405: 401: 397: 272: 210: 137: 133: 896: 5363: 5211: 4995: 4960: 4955: 4950: 4910: 4863: 4853: 4647: 4623: 4598: 4505: 4456: 4389: 4379: 4354: 4327: 4303: 4238: 3989: 3983: 2144: 1688: 1561: 1379: 693: 692:, that swell and shrink very regularly caused by the star's own mass 655: 629:

which determines the period of the star. Stars may also pulsate in a

537: 364: 353: 349: 252: 237: 233: 2455:"Observations of red-giant variable stars by Aboriginal Australians" 1744:, which undergo both frequent small outbursts, and rarer but larger 781:

stars, than do the type I Cepheids. The Type II have somewhat lower

646:. The study of stellar interiors using their pulsations is known as 427:

strong magnetic fields on the star betray themselves in the spectrum

31: 5356: 5057: 4731: 4490: 4463: 3511: 3354: 3268: 3243: 3014: 2961: 2875: 2538: 2471: 2402: 2285: 1859: 1695:

being the brightest in the recent history, reaching 2nd magnitude.

1605: 1519: 1459: 1172: 1058: 659: 634: 630: 497: 260: 2345: 1874: 5631: 5106: 4868: 4635: 4588: 4571: 4566: 4485: 3584: 3443:"Long-term photometric study of FK Comae Berenices and HD 199178" 2039: 1892: 1832: 1510: 1488: 1390: 1162: 667: 622:, where one part of the star expands while another part shrinks. 214: 2241:

Fröhlich, C. (2006). "Solar Irradiance Variability Since 1978".

1020: 727:, while a completely separate class of variables is named after 5621: 5609: 4828: 4714: 4083: 3396:"Rotating Variables: Mapping the Surfaces of the Stars | aavso" 2151:, and all of the planets and planet candidates detected by the 1992: 1986: 1593: 1567: 1467: 1463: 1455: 1178: 1066: 1062: 463: 3046: 2061: 2043: 1646: 1585: 1116: 589: 560: 202: 153: 3096:

Radial and Nonradial Pulsations as Probes of Stellar Physics

1891:

These stars rotate extremely rapidly (~100 km/s at the

618:, where the entire star expands and shrinks as a whole; and 4970: 4189: 3964: 1687:, depending on the behaviour of their light curve. Several 1663: 1658: 1242: 917: 533: 462:

is known to be driven by oscillations in the ionization of

149: 128: 5671: 4139: 1738:

are seen, part way between maximum and minimum brightness.

1540: 600:

Examples of types within these divisions are given below.

5336: 2199:

Alexeev, Boris V. (2017-01-01), Alexeev, Boris V. (ed.),

1296: 1199: 251:

gave the correct explanation of its variability in 1784.

186: 4158: 3531:"Irregularities of Period of Long Period Variable Stars" 3420:"MAST: Barbara A. Mikulski Archive for Space Telescopes" 2657: 1899:

in shape. They are (apparently) single giant stars with

3569: 3241: 1206:. Oscillations in the Sun are driven stochastically by 979:

Long-period variable star § Long secondary periods

1615:

A supernova may also result from mass transfer onto a

677: 392:

what kind of star is it: what is its temperature, its

5687: 3580:

Society for Popular Astronomy – Variable Star Section

2383: 1948: 374:

From the light curve the following data are derived:

3123:"Pulsating Hot Subdwarfs -- an Observational Review" 1734:, in which occasional plateaux of brightness called 1235: 577:

stars after the first recognized star in the class,

189:, for example, varies by about 0.1% over an 11-year 175:

has an orbiting companion that sometimes eclipses it

16:

Star whose brightness fluctuates, as seen from Earth

3570:

The American Association of Variable Star Observers

3242:Quirion, P.-O.; Fontaine, G.; Brassard, P. (2007). 1604:One of the most studied supernovae of this type is 851: 209:are also known to have observed the variability of 56:. Unsourced material may be challenged and removed. 1632:Images showing the expansion of the light echo of 1584:, left over from a supernova that was observed in 972: 388:From the spectrum the following data are derived: 381:what is the period of the brightness fluctuations? 4062: 3535:Monthly Notices of the Royal Astronomical Society 3528: 3483: 1525: 1491:regions caused by the rapid rotational velocity. 437: 181:Many, possibly most, stars exhibit at least some 5747: 3161: 1006: 998:Beta Cephei (β Cep) variables (sometimes called 916:, a 6 fold to 30,000 fold change in luminosity. 2686:"Variable Star Classification and Light Curves" 2201:"Chapter 7 - Nonlocal Theory of Variable Stars" 1869: 1580:. A well-known example of such a nebula is the 1419: 369:American Association of Variable Star Observers 2641:Contributions of 20th Century Women to Physics 2038:. When seen from certain angles, one star may 1959:Alpha Canum Venaticorum (α CVn) variables are 1671:) accelerates explosively. They form in close 1473: 734: 4174: 3600: 3440: 2573:. Sydney: Allen and Unwin. pp. 144–166. 1980: 1929: 1021:Very rapidly pulsating hot (subdwarf B) stars 312: 3058: 2819:Aerodynamic Phenomena in Stellar Atmospheres 2766:Journal of Astronomical History and Heritage 2526:Journal of Astronomical History and Heritage 2119: 2074: 332:Variable stars are generally analysed using 3282: 3248:The Astrophysical Journal Supplement Series 3061:Annual Review of Astronomy and Astrophysics 2982: 1818: 950: 603: 584: 4181: 4167: 3607: 3593: 3489: 3329: 3211:Encyclopedia of Astronomy and Astrophysics 1826: 1367: 1248: 1193: 1126: 1046: 3546: 3466: 3371: 3353: 3296: 3267: 3146: 3004: 2943: 2929: 2537: 2496: 2470: 2429: 2419: 2401: 2344: 1784: 1709:Dwarf novae are double stars involving a 1359: 1144: 836: 666:. In other cases, the restoring force is 116:Learn how and when to remove this message 3120: 3114: 2568: 2519: 2452: 2240: 2110: 2020: 1873: 1844: 1769: 1754: 1627: 1397:, and may be a different type of event. 1275: 1091: 987: 924: 884: 866: 814: 588: 316: 296: 185:in luminosity: the energy output of the 127: 3235: 3155: 2894: 2888: 2733:Burnell, S. Jocelyn Bell (2004-02-26). 2732: 2198: 2092: 1966: 1541:Cataclysmic or explosive variable stars 1442: 1332: 807:, they are occasionally referred to as 232:in 1596. This discovery, combined with 5748: 3529:Eddington, A.S.; Plakidis, S. (1929). 3208: 3164:"REVIEW: Physics of white dwarf stars" 3093: 2759: 2634: 2459:The Australian Journal of Anthropology 1839: 4162: 3588: 3434: 2593: 2133: 2017:Binary star § Eclipsing binaries 2010: 1412:timescale. The best known example is 1400: 1271: 1228:BLAP (Blue Large-Amplitude Pulsators) 1076: 788: 3441:Panov, K.; Dimitrov, D. (May 2007). 3412: 3202: 2736:An Introduction to the Sun and Stars 1623: 1031:The prototype of this rare class is 54:adding citations to reliable sources 25: 3422:. Space Telescope Science Institute 3162:Koester, D.; Chanmugam, G. (1990). 3087: 3081:10.1146/annurev.aa.16.090178.001243 2849: 2812: 1803: 765: 678:Cepheids and cepheid-like variables 291:General Catalogue of Variable Stars 13: 3614: 3127:Communications in Asteroseismology 2213:10.1016/b978-0-444-64019-2.00007-7 2049: 1943: 1306: 1069:lines are extra strong, a type of 662:mode of pulsation, abbreviated to 14: 5777: 3563: 2786:10.3724/SP.J.1440-2807.2004.02.01 2637:"Cecilia Helena Payne-Gaposchkin" 2548:10.3724/SP.J.1440-2807.2018.01.02 1955:Alpha2 Canum Venaticorum variable 1949:Alpha Canum Venaticorum variables 1776:Polar (cataclysmic variable star) 1295:Variability of more massive (2–8 1236:Fast yellow pulsating supergiants 1221: 880: 503: 5733: 5721: 5709: 5697: 5670: 5660: 5659: 4138: 2660:Odessa Astronomical Publications 2384:Jetsu, L.; Porceddu, S. (2015). 2290:Cambridge Archaeological Journal 1853: 1123:is the prototype of this class. 1027:Subdwarf B star § Variables 852:Rapidly oscillating Ap variables 723:The Cepheids are named only for 593:Intrinsic variable types in the 466:(from He to He and back to He). 30: 3522: 3388: 3276: 3052: 3029: 2976: 2923: 2843: 2806: 2753: 2726: 2702: 2678: 2651: 2628: 2604: 1435:(R CrB) is the prototype star. 1317:Orion variables are young, hot 973:Long secondary period variables 758:, discovered to be variable by 469: 41:needs additional citations for 3168:Reports on Progress in Physics 2852:"1963ApJ...138..487C Page 487" 2739:. Cambridge University Press. 2587: 2562: 2513: 2446: 2377: 2324: 2277: 2234: 2207:, Elsevier, pp. 321–377, 2192: 1698: 1526:RS Canum Venaticorum variables 1494: 1210:in its outer layers. The term 833:is usually between A0 and F5. 438:Interpretation of observations 152:whose brightness as seen from 1: 5572:Timeline of stellar astronomy 3728:Blue large-amplitude pulsator 2762:"2004JAHH....7...65M Page 65" 2185: 1555: 1532:RS Canum Venaticorum variable 1257: 1007:Slowly pulsating B-type stars 508:Variable stars may be either 348:. For regular variables, the 3049:. Accessed October 2, 2008. 2917:10.1016/j.newast.2007.04.002 2815:"1967IAUS...28....3C Page 3" 2635:Turner, J (March 16, 2001). 2597:The Stars Of High Luminosity 2421:10.1371/journal.pone.0144140 1870:FK Comae Berenices variables 1420:R Coronae Borealis variables 1013:Slowly pulsating B-type star 750:detected the variability of 321:A photogenic variable star, 196: 7: 5232:Hertzsprung–Russell diagram 3315:10.1051/0004-6361:200400079 2158: 1474:Gamma Cassiopeiae variables 1426:R Coronae Borealis variable 858:Rapidly oscillating Ap star 735:Classical Cepheid variables 595:Hertzsprung–Russell diagram 10: 5782: 5146:Kelvin–Helmholtz mechanism 3468:10.1051/0004-6361:20065596 3447:Astronomy and Astrophysics 3285:Astronomy and Astrophysics 3188:10.1088/0034-4885/53/7/001 2594:Payne, Cecilia H. (1930). 2123: 2096: 2078: 2053: 2046:, or Beta Persei (β Per). 2014: 1984: 1981:Optically variable pulsars 1970: 1952: 1933: 1930:BY Draconis variable stars 1807: 1788: 1773: 1758: 1702: 1691:novae have been recorded, 1656: 1638: 1559: 1544: 1529: 1498: 1480:Gamma Cassiopeiae variable 1477: 1446: 1423: 1404: 1371: 1336: 1325:variables. Variability of 1310: 1288: 1261: 1225: 1148: 1130: 1119:, in the constellation of 1095: 1080: 1050: 1024: 1010: 991: 976: 954: 928: 901: 870: 855: 840: 818: 792: 769: 741:Classical Cepheid variable 738: 681: 607: 473: 313:Variable star observations 289:The latest edition of the 255:was identified in 1686 by 18: 5655: 5580: 5429: 5327: 5255: 5154: 5011: 4886: 4764: 4673: 4409: 4400: 4279: 4209: 4196: 4188: 4134: 4101: 4071: 4050: 4034: 4027: 3940: 3905: 3879: 3844: 3801: 3794: 3764: 3736: 3698: 3631: 3622: 3342:The Astrophysical Journal 2985:The Astrophysical Journal 2932:The Astrophysical Journal 2856:The Astrophysical Journal 2363:10.1088/0004-637X/773/1/1 2333:The Astrophysical Journal 2310:10.1017/S0959774308000395 2263:10.1007/s11214-006-9046-5 2120:W Ursae Majoris variables 2075:Double Periodic variables 1810:AM Canum Venaticorum star 1547:Cataclysmic variable star 476:Variable star designation 5525:With multiple exoplanets 3541:(1). London, UK: 65–71. 3373:10.3847/1538-4357/abb318 2396:(12): e.0144140 (23pp). 2126:W Ursae Majoris variable 2081:Double periodic variable 1903:G and K and show strong 1819:Extrinsic variable stars 1652: 1061:while on the other hand 951:Slow irregular variables 604:Pulsating variable stars 585:Intrinsic variable stars 546:Extrinsic variable stars 521:Intrinsic variable stars 448:Arthur Stanley Eddington 278:In 1930, astrophysicist 4311:Asymptotic giant branch 3777:Solar-like oscillations 3718:Slowly pulsating B-type 3459:2007A&A...467..229P 3307:2004A&A...426L..45N 3073:1978ARA&A..16..215L 2569:Hamacher, D.W. (2022). 2520:Schaefer, B.E. (2018). 2453:Hamacher, D.W. (2018). 1827:Rotating variable stars 1551:Symbiotic variable star 1368:Luminous blue variables 1319:pre–main-sequence stars 1249:Eruptive variable stars 1212:solar-like oscillations 1194:Solar-like oscillations 1127:Gamma Doradus variables 1047:PV Telescopii variables 957:Slow irregular variable 910:Asymptotic giant branch 490:Friedrich W. Argelander 5647:Tidal disruption event 5136:Circumstellar envelope 4370:Luminous blue variable 3854:Luminous blue variable 3685:Rapidly oscillating Ap 3575:GCVS Variability Types 2175:List of variable stars 2030: 1995:have been detected in 1888: 1785:Z Andromedae variables 1742:SU Ursae Majoris stars 1732:Z Camelopardalis stars 1724:after the variable in 1636: 1610:Large Magellanic Cloud 1374:Luminous blue variable 1360:Giants and supergiants 1286: 1264:Pre–main-sequence star 1145:Pulsating white dwarfs 1133:Gamma Doradus variable 1053:PV Telescopii variable 899: 837:SX Phoenicis variables 597: 329: 207:Aboriginal Australians 141: 5766:Concepts in astronomy 5172:Effective temperature 3548:10.1093/mnras/90.1.65 3492:Astrophysical Journal 3209:Murdin, Paul (2002). 3121:Kilkenny, D. (2007). 2850:Cox, John P. (1963). 2760:Mestel, Leon (2004). 2571:The First Astronomers 2243:Space Science Reviews 2205:Nonlocal Astrophysics 2111:W Serpentis variables 2024: 1877: 1845:Ellipsoidal variables 1791:Z Andromedae variable 1770:AM Herculis variables 1755:DQ Herculis variables 1631: 1279: 1151:Pulsating white dwarf 1092:Alpha Cygni variables 988:Beta Cephei variables 925:Semiregular variables 888: 867:Long period variables 843:SX Phoenicis variable 815:Delta Scuti variables 698:fundamental frequency 670:and this is called a 627:fundamental frequency 592: 352:of variation and its 320: 297:Detecting variability 131: 5642:Planet-hosting stars 5520:With resolved images 5491:Historical brightest 5421:Photometric-standard 5347:Solar radio emission 5141:Eddington luminosity 4921:Triple-alpha process 4859:Thorne–Żytkow object 4234:Young stellar object 4042:Rotating ellipsoidal 3950:AM Canum Venaticorum 3897:RS Canum Venaticorum 2647:on October 12, 2012. 2093:Beta Lyrae variables 1967:SX Arietis variables 1936:BY Draconis variable 1831:Stars with sizeable 1509:, also known as the 1443:Wolf–Rayet variables 1333:FU Orionis variables 1098:Alpha Cygni variable 994:Beta Cephei variable 931:Semiregular variable 873:Long period variable 821:Delta Scuti variable 762:a few months later. 559:where, as seen from 551:Eclipsing binaries, 50:improve this article 5466:Highest temperature 5237:Color–color diagram 5102:Protoplanetary disk 4906:Proton–proton chain 4584:Chemically peculiar 4079:α Canum Venaticorum 3504:1988ApJ...329..764L 3364:2020ApJ...902...24D 3260:2007ApJS..171..219Q 3219:2002eaa..book.....M 3180:1990RPPh...53..837K 3139:2007CoAst.150..234K 3108:2002ASPC..259..196D 2997:2003ApJ...584.1035O 2954:2007ApJ...660.1486S 2909:2007NewA...12..556M 2868:1963ApJ...138..487C 2831:1967IAUS...28....3C 2813:Cox, J. P. (1967). 2778:2004JAHH....7...65M 2672:2001OAP....14..266S 2481:2018AuJAn..29...89H 2412:2015PLoSO..1044140J 2355:2013ApJ...773....1J 2302:2008CArcJ..18..327P 2255:2006SSRv..125...53F 2099:Beta Lyrae variable 1973:SX Arietis variable 1840:Non-spherical stars 1572:Chandrasekhar limit 1437:DY Persei variables 1395:supernova impostors 1071:Extreme helium star 1035:, a 15th magnitude 908:Mira variables are 696:, generally by the 361:Amateur astronomers 245:Geminiano Montanari 171:Extrinsic variables 165:Intrinsic variables 19:For the novel, see 5471:Lowest temperature 5222:Photometric system 5192:Absolute magnitude 5126:Circumstellar dust 4739:Stellar black hole 4375:Stellar population 4261:Herbig–Haro object 4063:FK Comae Berenices 3859:R Coronae Borealis 3649:Classical cepheids 3148:10.1553/cia150s234 3041:2010-06-15 at the 2616:www.britannica.com 2489:10.1111/taja.12257 2170:Irregular variable 2134:Planetary transits 2031: 2029:vary in brightness 2027:eclipsing binaries 2011:Eclipsing binaries 1895:); hence they are 1889: 1761:Intermediate polar 1722:SS Cygni variables 1637: 1577:supernova remnants 1433:R Coronae Borealis 1401:Yellow hypergiants 1378:Also known as the 1301:Herbig Ae/Be stars 1291:Herbig Ae/Be stars 1287: 1272:Herbig Ae/Be stars 1077:RV Tauri variables 1000:Beta Canis Majoris 900: 789:RR Lyrae variables 598: 330: 325:, embedded in the 158:apparent magnitude 142: 5685: 5684: 5588:Substellar object 5567:Planetary nebulae 4986:Luminous red nova 4896:Deuterium burning 4882: 4881: 4365:Instability strip 4345:Wolf-Rayet nebula 4299:Horizontal branch 4244:Pre-main-sequence 4156: 4155: 4121:Planetary transit 4097: 4096: 4018: 4011: 3992: 3978: 3960:Luminous red nova 3936: 3935: 3918:Gamma Cassiopeiae 3871:Yellow hypergiant 3867: 3835: 3828: 3790: 3789: 3676: 3656: 2746:978-0-521-54622-5 2222:978-0-444-64019-2 2180:Stellar pulsation 1718:U Geminorum stars 1669:degenerate matter 1641:Luminous red nova 1624:Luminous red nova 1485:Gamma Cassiopeiae 1407:Yellow hypergiant 1281:Herbig Ae/Be star 1083:RV Tauri variable 805:globular clusters 795:RR Lyrae variable 710:Henrietta Leavitt 690:instability strip 610:Stellar pulsation 557:planetary systems 488:was developed by 484:. This system of 458:The pulsation of 338:spectrophotometry 284:Cepheid variables 222:Johannes Holwarda 126: 125: 118: 100: 5773: 5738: 5737: 5736: 5726: 5725: 5724: 5714: 5713: 5712: 5702: 5701: 5700: 5693: 5677:Stars portal 5675: 5674: 5663: 5662: 5319:Planetary system 5242:Strömgren sphere 5114:Asteroseismology 4835:Black hole star 4407: 4406: 4333:Planetary nebula 4294:Red-giant branch 4183: 4176: 4169: 4160: 4159: 4143: 4142: 4032: 4031: 4014: 4007: 3988: 3974: 3892:FS Canis Majoris 3861: 3831: 3824: 3799: 3798: 3662: 3646: 3629: 3628: 3609: 3602: 3595: 3586: 3585: 3559: 3557: 3555: 3550: 3516: 3515: 3487: 3481: 3480: 3470: 3438: 3432: 3431: 3429: 3427: 3416: 3410: 3409: 3407: 3406: 3392: 3386: 3385: 3375: 3357: 3333: 3327: 3326: 3300: 3298:astro-ph/0409243 3280: 3274: 3273: 3271: 3239: 3233: 3232: 3206: 3200: 3199: 3159: 3153: 3152: 3150: 3118: 3112: 3111: 3091: 3085: 3084: 3056: 3050: 3033: 3027: 3026: 3008: 2980: 2974: 2973: 2947: 2945:astro-ph/0701463 2938:(2): 1486–1491. 2927: 2921: 2920: 2892: 2886: 2885: 2883: 2882: 2847: 2841: 2840: 2838: 2837: 2810: 2804: 2803: 2801: 2800: 2757: 2751: 2750: 2730: 2724: 2723: 2721: 2720: 2706: 2700: 2699: 2697: 2695: 2690: 2682: 2676: 2675: 2655: 2649: 2648: 2643:. Archived from 2632: 2626: 2625: 2623: 2622: 2608: 2602: 2601: 2591: 2585: 2584: 2566: 2560: 2559: 2541: 2517: 2511: 2510: 2500: 2474: 2450: 2444: 2443: 2433: 2423: 2405: 2381: 2375: 2374: 2348: 2339:(1): A1 (14pp). 2328: 2322: 2321: 2281: 2275: 2274: 2238: 2232: 2231: 2230: 2229: 2196: 1924:(contact) binary 1804:AM CVn variables 1634:V838 Monocerotis 1516:Proxima Centauri 1216:asteroseismology 1139:spectral classes 1104:spectral classes 809:cluster Cepheids 772:Type II Cepheids 766:Type II Cepheids 700:. Generally the 684:Cepheid variable 648:asteroseismology 394:luminosity class 121: 114: 110: 107: 101: 99: 58: 34: 26: 5781: 5780: 5776: 5775: 5774: 5772: 5771: 5770: 5746: 5745: 5744: 5734: 5732: 5722: 5720: 5710: 5708: 5698: 5696: 5688: 5686: 5681: 5669: 5651: 5576: 5545:Milky Way novae 5481:Smallest volume 5425: 5406:Radial velocity 5329: 5323: 5275:Common envelope 5251: 5150: 5119:Helioseismology 5090:Bipolar outflow 5031:Microturbulence 5026:Convection zone 5007: 4901:Lithium burning 4888:Nucleosynthesis 4878: 4760: 4669: 4396: 4275: 4224:Molecular cloud 4205: 4192: 4187: 4157: 4152: 4145:Star portal 4137: 4130: 4126:W Ursae Majoris 4093: 4072:Magnetic fields 4067: 4046: 4023: 3932: 3901: 3887:Double periodic 3880:Eruptive binary 3875: 3846: 3840: 3786: 3760: 3732: 3700: 3699:Blue-white with 3694: 3636: 3618: 3613: 3566: 3553: 3551: 3525: 3520: 3519: 3488: 3484: 3439: 3435: 3425: 3423: 3418: 3417: 3413: 3404: 3402: 3394: 3393: 3389: 3334: 3330: 3281: 3277: 3240: 3236: 3229: 3207: 3203: 3160: 3156: 3119: 3115: 3092: 3088: 3057: 3053: 3043:Wayback Machine 3034: 3030: 3006:10.1.1.514.3679 2981: 2977: 2928: 2924: 2893: 2889: 2880: 2878: 2848: 2844: 2835: 2833: 2811: 2807: 2798: 2796: 2758: 2754: 2747: 2731: 2727: 2718: 2716: 2708: 2707: 2703: 2693: 2691: 2688: 2684: 2683: 2679: 2656: 2652: 2633: 2629: 2620: 2618: 2610: 2609: 2605: 2592: 2588: 2581: 2567: 2563: 2518: 2514: 2451: 2447: 2382: 2378: 2329: 2325: 2282: 2278: 2239: 2235: 2227: 2225: 2223: 2197: 2193: 2188: 2161: 2149:GSC 02652-01324 2136: 2128: 2122: 2113: 2101: 2095: 2083: 2077: 2058: 2052: 2050:Algol variables 2019: 2013: 1989: 1983: 1975: 1969: 1957: 1951: 1946: 1944:Magnetic fields 1938: 1932: 1910:. Examples are 1872: 1856: 1847: 1842: 1829: 1821: 1812: 1806: 1793: 1787: 1778: 1772: 1763: 1757: 1707: 1701: 1693:Nova Cygni 1975 1661: 1655: 1643: 1626: 1564: 1558: 1553: 1545:Main articles: 1543: 1534: 1528: 1503: 1497: 1482: 1476: 1451: 1449:Wolf–Rayet star 1445: 1428: 1422: 1414:Rho Cassiopeiae 1409: 1403: 1376: 1370: 1362: 1341: 1339:FU Orionis star 1335: 1315: 1309: 1307:Orion variables 1293: 1274: 1266: 1260: 1251: 1238: 1230: 1224: 1204:helioseismology 1196: 1153: 1147: 1135: 1129: 1113: 1109: 1100: 1094: 1085: 1079: 1055: 1049: 1037:subdwarf B star 1029: 1023: 1015: 1009: 996: 990: 981: 975: 959: 953: 933: 927: 906: 883: 875: 869: 860: 854: 845: 839: 823: 817: 797: 791: 774: 768: 743: 737: 702:Eddington valve 686: 680: 612: 606: 587: 506: 478: 472: 440: 315: 305:. By combining 299: 230:David Fabricius 199: 122: 111: 105: 102: 65:"Variable star" 59: 57: 47: 35: 24: 17: 12: 11: 5: 5779: 5769: 5768: 5763: 5758: 5756:Variable stars 5743: 5742: 5730: 5718: 5706: 5683: 5682: 5680: 5679: 5667: 5656: 5653: 5652: 5650: 5649: 5644: 5639: 5634: 5629: 5624: 5619: 5614: 5613: 5612: 5607: 5606: 5605: 5600: 5584: 5582: 5578: 5577: 5575: 5574: 5569: 5564: 5563: 5562: 5557: 5547: 5542: 5537: 5532: 5527: 5522: 5517: 5516: 5515: 5510: 5509: 5508: 5498: 5493: 5488: 5483: 5478: 5476:Largest volume 5473: 5468: 5463: 5453: 5452: 5451: 5446: 5435: 5433: 5427: 5426: 5424: 5423: 5418: 5413: 5408: 5403: 5402: 5401: 5396: 5391: 5381: 5376: 5371: 5366: 5361: 5360: 5359: 5354: 5349: 5344: 5333: 5331: 5325: 5324: 5322: 5321: 5316: 5315: 5314: 5309: 5304: 5294: 5289: 5288: 5287: 5282: 5277: 5272: 5261: 5259: 5253: 5252: 5250: 5249: 5244: 5239: 5234: 5229: 5224: 5219: 5214: 5209: 5204: 5199: 5194: 5189: 5187:Magnetic field 5184: 5179: 5174: 5169: 5164: 5158: 5156: 5152: 5151: 5149: 5148: 5143: 5138: 5133: 5128: 5123: 5122: 5121: 5111: 5110: 5109: 5104: 5097:Accretion disk 5094: 5093: 5092: 5087: 5077: 5076: 5075: 5073:Alfvén surface 5070: 5068:Stellar corona 5065: 5060: 5055: 5045: 5043:Radiation zone 5040: 5039: 5038: 5033: 5023: 5017: 5015: 5009: 5008: 5006: 5005: 5000: 4999: 4998: 4993: 4988: 4983: 4978: 4968: 4963: 4958: 4953: 4948: 4943: 4938: 4933: 4928: 4923: 4918: 4913: 4908: 4903: 4898: 4892: 4890: 4884: 4883: 4880: 4879: 4877: 4876: 4871: 4866: 4861: 4856: 4851: 4850: 4849: 4844: 4841: 4833: 4832: 4831: 4826: 4821: 4816: 4811: 4806: 4801: 4796: 4791: 4781: 4776: 4770: 4768: 4762: 4761: 4759: 4758: 4753: 4752: 4751: 4741: 4736: 4735: 4734: 4729: 4728: 4727: 4722: 4712: 4702: 4701: 4700: 4690: 4685: 4679: 4677: 4671: 4670: 4668: 4667: 4665:Blue straggler 4662: 4661: 4660: 4650: 4645: 4644: 4643: 4633: 4632: 4631: 4626: 4621: 4616: 4611: 4606: 4601: 4596: 4591: 4581: 4576: 4575: 4574: 4569: 4564: 4554: 4553: 4552: 4542: 4541: 4540: 4535: 4530: 4520: 4515: 4514: 4513: 4508: 4503: 4493: 4488: 4483: 4478: 4477: 4476: 4471: 4461: 4460: 4459: 4454: 4449: 4444: 4439: 4434: 4429: 4423:Main sequence 4421: 4416: 4410: 4404: 4402:Classification 4398: 4397: 4395: 4394: 4393: 4392: 4387: 4377: 4372: 4367: 4362: 4357: 4352: 4347: 4342: 4341: 4340: 4338:Protoplanetary 4330: 4325: 4324: 4323: 4318: 4308: 4307: 4306: 4296: 4291: 4285: 4283: 4277: 4276: 4274: 4273: 4268: 4263: 4258: 4257: 4256: 4251: 4246: 4241: 4231: 4226: 4221: 4215: 4213: 4207: 4206: 4204: 4203: 4197: 4194: 4193: 4186: 4185: 4178: 4171: 4163: 4154: 4153: 4135: 4132: 4131: 4129: 4128: 4123: 4118: 4113: 4107: 4105: 4099: 4098: 4095: 4094: 4092: 4091: 4086: 4081: 4075: 4073: 4069: 4068: 4066: 4065: 4060: 4054: 4052: 4048: 4047: 4045: 4044: 4038: 4036: 4029: 4025: 4024: 4022: 4021: 4020: 4019: 4012: 4009:Symbiotic nova 4000: 3995: 3994: 3993: 3981: 3980: 3979: 3967: 3962: 3957: 3952: 3946: 3944: 3938: 3937: 3934: 3933: 3931: 3930: 3925: 3923:Lambda Eridani 3920: 3915: 3909: 3907: 3903: 3902: 3900: 3899: 3894: 3889: 3883: 3881: 3877: 3876: 3874: 3873: 3868: 3856: 3850: 3848: 3842: 3841: 3839: 3838: 3837: 3836: 3829: 3817: 3811: 3809: 3796: 3792: 3791: 3788: 3787: 3785: 3784: 3779: 3774: 3768: 3766: 3762: 3761: 3759: 3758: 3756:Slow irregular 3753: 3748: 3742: 3740: 3734: 3733: 3731: 3730: 3725: 3720: 3715: 3710: 3704: 3702: 3696: 3695: 3693: 3692: 3687: 3682: 3677: 3657: 3640: 3638: 3626: 3620: 3619: 3616:Variable stars 3612: 3611: 3604: 3597: 3589: 3583: 3582: 3577: 3572: 3565: 3564:External links 3562: 3561: 3560: 3524: 3521: 3518: 3517: 3512:10.1086/166419 3482: 3453:(1): 229–235. 3433: 3411: 3387: 3328: 3275: 3269:10.1086/513870 3254:(1): 219–248. 3234: 3227: 3201: 3154: 3113: 3086: 3051: 3045:, John Percy, 3028: 3015:10.1086/345715 2975: 2962:10.1086/513012 2922: 2903:(7): 556–561. 2887: 2876:10.1086/147661 2842: 2805: 2752: 2745: 2725: 2701: 2677: 2650: 2627: 2603: 2586: 2579: 2561: 2512: 2445: 2376: 2323: 2296:(3): 327–339. 2276: 2249:(1–4): 53–65. 2233: 2221: 2190: 2189: 2187: 2184: 2183: 2182: 2177: 2172: 2167: 2160: 2157: 2153:Kepler Mission 2135: 2132: 2124:Main article: 2121: 2118: 2112: 2109: 2097:Main article: 2094: 2091: 2079:Main article: 2076: 2073: 2056:Algol variable 2054:Main article: 2051: 2048: 2015:Main article: 2012: 2009: 1985:Main article: 1982: 1979: 1971:Main article: 1968: 1965: 1953:Main article: 1950: 1947: 1945: 1942: 1934:Main article: 1931: 1928: 1908:emission lines 1901:spectral types 1871: 1868: 1862:). The star's 1855: 1852: 1846: 1843: 1841: 1838: 1836:the observer. 1828: 1825: 1820: 1817: 1808:Main article: 1805: 1802: 1789:Main article: 1786: 1783: 1774:Main article: 1771: 1768: 1759:Main article: 1756: 1753: 1752: 1751: 1747:superoutbursts 1739: 1729: 1703:Main article: 1700: 1697: 1673:binary systems 1657:Main article: 1654: 1651: 1639:Main article: 1625: 1622: 1560:Main article: 1557: 1554: 1542: 1539: 1530:Main article: 1527: 1524: 1499:Main article: 1496: 1493: 1478:Main article: 1475: 1472: 1447:Main article: 1444: 1441: 1424:Main article: 1421: 1418: 1405:Main article: 1402: 1399: 1372:Main article: 1369: 1366: 1361: 1358: 1337:Main article: 1334: 1331: 1313:Orion variable 1311:Main article: 1308: 1305: 1289:Main article: 1273: 1270: 1262:Main article: 1259: 1256: 1250: 1247: 1245:observations. 1237: 1234: 1226:Main article: 1223: 1222:BLAP variables 1220: 1195: 1192: 1149:Main article: 1146: 1143: 1131:Main article: 1128: 1125: 1111: 1107: 1096:Main article: 1093: 1090: 1081:Main article: 1078: 1075: 1051:Main article: 1048: 1045: 1025:Main article: 1022: 1019: 1011:Main article: 1008: 1005: 992:Main article: 989: 986: 977:Main article: 974: 971: 955:Main article: 952: 949: 929:Main article: 926: 923: 902:Main article: 882: 881:Mira variables 879: 871:Main article: 868: 865: 856:Main article: 853: 850: 841:Main article: 838: 835: 827:Dwarf Cepheids 819:Main article: 816: 813: 793:Main article: 790: 787: 770:Main article: 767: 764: 760:John Goodricke 739:Main article: 736: 733: 682:Main article: 679: 676: 608:Main article: 605: 602: 586: 583: 571: 570: 569: 568: 564: 543: 542: 541: 530: 527: 505: 504:Classification 502: 474:Main article: 471: 468: 439: 436: 432: 431: 428: 425: 422:Doppler effect 418: 415: 412: 409: 386: 385: 382: 379: 314: 311: 298: 295: 249:John Goodricke 198: 195: 179: 178: 168: 132:Comparison of 124: 123: 38: 36: 29: 15: 9: 6: 4: 3: 2: 5778: 5767: 5764: 5762: 5759: 5757: 5754: 5753: 5751: 5741: 5731: 5729: 5719: 5717: 5707: 5705: 5695: 5694: 5691: 5678: 5673: 5668: 5666: 5658: 5657: 5654: 5648: 5645: 5643: 5640: 5638: 5637:Intergalactic 5635: 5633: 5630: 5628: 5625: 5623: 5620: 5618: 5617:Galactic year 5615: 5611: 5608: 5604: 5601: 5599: 5596: 5595: 5594: 5591: 5590: 5589: 5586: 5585: 5583: 5579: 5573: 5570: 5568: 5565: 5561: 5558: 5556: 5553: 5552: 5551: 5548: 5546: 5543: 5541: 5538: 5536: 5533: 5531: 5528: 5526: 5523: 5521: 5518: 5514: 5511: 5507: 5504: 5503: 5502: 5499: 5497: 5496:Most luminous 5494: 5492: 5489: 5487: 5484: 5482: 5479: 5477: 5474: 5472: 5469: 5467: 5464: 5462: 5459: 5458: 5457: 5454: 5450: 5447: 5445: 5442: 5441: 5440: 5437: 5436: 5434: 5432: 5428: 5422: 5419: 5417: 5414: 5412: 5411:Proper motion 5409: 5407: 5404: 5400: 5397: 5395: 5392: 5390: 5387: 5386: 5385: 5382: 5380: 5377: 5375: 5374:Constellation 5372: 5370: 5367: 5365: 5362: 5358: 5355: 5353: 5350: 5348: 5345: 5343: 5342:Solar eclipse 5340: 5339: 5338: 5335: 5334: 5332: 5328:Earth-centric 5326: 5320: 5317: 5313: 5310: 5308: 5305: 5303: 5300: 5299: 5298: 5295: 5293: 5290: 5286: 5283: 5281: 5278: 5276: 5273: 5271: 5268: 5267: 5266: 5263: 5262: 5260: 5258: 5254: 5248: 5245: 5243: 5240: 5238: 5235: 5233: 5230: 5228: 5225: 5223: 5220: 5218: 5215: 5213: 5210: 5208: 5205: 5203: 5200: 5198: 5195: 5193: 5190: 5188: 5185: 5183: 5180: 5178: 5175: 5173: 5170: 5168: 5165: 5163: 5160: 5159: 5157: 5153: 5147: 5144: 5142: 5139: 5137: 5134: 5132: 5129: 5127: 5124: 5120: 5117: 5116: 5115: 5112: 5108: 5105: 5103: 5100: 5099: 5098: 5095: 5091: 5088: 5086: 5083: 5082: 5081: 5078: 5074: 5071: 5069: 5066: 5064: 5061: 5059: 5056: 5054: 5051: 5050: 5049: 5046: 5044: 5041: 5037: 5034: 5032: 5029: 5028: 5027: 5024: 5022: 5019: 5018: 5016: 5014: 5010: 5004: 5001: 4997: 4994: 4992: 4989: 4987: 4984: 4982: 4979: 4977: 4974: 4973: 4972: 4969: 4967: 4964: 4962: 4959: 4957: 4954: 4952: 4949: 4947: 4944: 4942: 4939: 4937: 4934: 4932: 4929: 4927: 4926:Alpha process 4924: 4922: 4919: 4917: 4914: 4912: 4909: 4907: 4904: 4902: 4899: 4897: 4894: 4893: 4891: 4889: 4885: 4875: 4872: 4870: 4867: 4865: 4862: 4860: 4857: 4855: 4852: 4848: 4845: 4842: 4840: 4837: 4836: 4834: 4830: 4827: 4825: 4822: 4820: 4817: 4815: 4812: 4810: 4807: 4805: 4802: 4800: 4797: 4795: 4792: 4790: 4787: 4786: 4785: 4782: 4780: 4777: 4775: 4772: 4771: 4769: 4767: 4763: 4757: 4754: 4750: 4747: 4746: 4745: 4742: 4740: 4737: 4733: 4730: 4726: 4723: 4721: 4718: 4717: 4716: 4713: 4711: 4708: 4707: 4706: 4703: 4699: 4698:Helium planet 4696: 4695: 4694: 4691: 4689: 4688:Parker's star 4686: 4684: 4681: 4680: 4678: 4676: 4672: 4666: 4663: 4659: 4656: 4655: 4654: 4651: 4649: 4646: 4642: 4639: 4638: 4637: 4634: 4630: 4627: 4625: 4622: 4620: 4619:Lambda Boötis 4617: 4615: 4612: 4610: 4607: 4605: 4602: 4600: 4597: 4595: 4592: 4590: 4587: 4586: 4585: 4582: 4580: 4577: 4573: 4570: 4568: 4565: 4563: 4560: 4559: 4558: 4555: 4551: 4548: 4547: 4546: 4543: 4539: 4536: 4534: 4531: 4529: 4526: 4525: 4524: 4521: 4519: 4516: 4512: 4509: 4507: 4504: 4502: 4499: 4498: 4497: 4494: 4492: 4489: 4487: 4484: 4482: 4479: 4475: 4472: 4470: 4467: 4466: 4465: 4462: 4458: 4455: 4453: 4450: 4448: 4445: 4443: 4440: 4438: 4435: 4433: 4430: 4428: 4425: 4424: 4422: 4420: 4417: 4415: 4412: 4411: 4408: 4405: 4403: 4399: 4391: 4388: 4386: 4385:Superluminous 4383: 4382: 4381: 4378: 4376: 4373: 4371: 4368: 4366: 4363: 4361: 4358: 4356: 4353: 4351: 4348: 4346: 4343: 4339: 4336: 4335: 4334: 4331: 4329: 4326: 4322: 4319: 4317: 4314: 4313: 4312: 4309: 4305: 4302: 4301: 4300: 4297: 4295: 4292: 4290: 4289:Main sequence 4287: 4286: 4284: 4282: 4278: 4272: 4269: 4267: 4266:Hayashi track 4264: 4262: 4259: 4255: 4252: 4250: 4247: 4245: 4242: 4240: 4237: 4236: 4235: 4232: 4230: 4227: 4225: 4222: 4220: 4217: 4216: 4214: 4212: 4208: 4202: 4199: 4198: 4195: 4191: 4184: 4179: 4177: 4172: 4170: 4165: 4164: 4161: 4151: 4147: 4146: 4141: 4133: 4127: 4124: 4122: 4119: 4117: 4114: 4112: 4109: 4108: 4106: 4104: 4100: 4090: 4087: 4085: 4082: 4080: 4077: 4076: 4074: 4070: 4064: 4061: 4059: 4056: 4055: 4053: 4051:Stellar spots 4049: 4043: 4040: 4039: 4037: 4035:Non-spherical 4033: 4030: 4026: 4017: 4013: 4010: 4006: 4005: 4004: 4001: 3999: 3996: 3991: 3987: 3986: 3985: 3982: 3977: 3973: 3972: 3971: 3968: 3966: 3963: 3961: 3958: 3956: 3953: 3951: 3948: 3947: 3945: 3943: 3939: 3929: 3926: 3924: 3921: 3919: 3916: 3914: 3911: 3910: 3908: 3904: 3898: 3895: 3893: 3890: 3888: 3885: 3884: 3882: 3878: 3872: 3869: 3865: 3860: 3857: 3855: 3852: 3851: 3849: 3843: 3834: 3830: 3827: 3823: 3822: 3821: 3818: 3816: 3813: 3812: 3810: 3808: 3804: 3800: 3797: 3793: 3783: 3780: 3778: 3775: 3773: 3772:Gamma Doradus 3770: 3769: 3767: 3763: 3757: 3754: 3752: 3749: 3747: 3744: 3743: 3741: 3739: 3735: 3729: 3726: 3724: 3723:PV Telescopii 3721: 3719: 3716: 3714: 3711: 3709: 3706: 3705: 3703: 3701:early spectra 3697: 3691: 3688: 3686: 3683: 3681: 3678: 3674: 3670: 3666: 3661: 3658: 3654: 3650: 3645: 3642: 3641: 3639: 3634: 3630: 3627: 3625: 3621: 3617: 3610: 3605: 3603: 3598: 3596: 3591: 3590: 3587: 3581: 3578: 3576: 3573: 3571: 3568: 3567: 3549: 3544: 3540: 3536: 3532: 3527: 3526: 3513: 3509: 3505: 3501: 3497: 3493: 3486: 3478: 3474: 3469: 3464: 3460: 3456: 3452: 3448: 3444: 3437: 3421: 3415: 3401: 3400:www.aavso.org 3397: 3391: 3383: 3379: 3374: 3369: 3365: 3361: 3356: 3351: 3347: 3343: 3339: 3332: 3324: 3320: 3316: 3312: 3308: 3304: 3299: 3294: 3290: 3286: 3279: 3270: 3265: 3261: 3257: 3253: 3249: 3245: 3238: 3230: 3228:0-333-75088-8 3224: 3220: 3216: 3212: 3205: 3197: 3193: 3189: 3185: 3181: 3177: 3173: 3169: 3165: 3158: 3149: 3144: 3140: 3136: 3132: 3128: 3124: 3117: 3109: 3105: 3101: 3097: 3090: 3082: 3078: 3074: 3070: 3066: 3062: 3055: 3048: 3044: 3040: 3037: 3032: 3024: 3020: 3016: 3012: 3007: 3002: 2998: 2994: 2990: 2986: 2979: 2971: 2967: 2963: 2959: 2955: 2951: 2946: 2941: 2937: 2933: 2926: 2918: 2914: 2910: 2906: 2902: 2898: 2897:New Astronomy 2891: 2877: 2873: 2869: 2865: 2861: 2857: 2853: 2846: 2832: 2828: 2824: 2820: 2816: 2809: 2795: 2791: 2787: 2783: 2779: 2775: 2771: 2767: 2763: 2756: 2748: 2742: 2738: 2737: 2729: 2715: 2711: 2705: 2687: 2681: 2673: 2669: 2665: 2661: 2654: 2646: 2642: 2638: 2631: 2617: 2613: 2607: 2599: 2598: 2590: 2582: 2580:9781760877200 2576: 2572: 2565: 2557: 2553: 2549: 2545: 2540: 2535: 2531: 2527: 2523: 2516: 2508: 2504: 2499: 2494: 2490: 2486: 2482: 2478: 2473: 2468: 2465:(1): 89–107. 2464: 2460: 2456: 2449: 2441: 2437: 2432: 2427: 2422: 2417: 2413: 2409: 2404: 2399: 2395: 2391: 2387: 2380: 2372: 2368: 2364: 2360: 2356: 2352: 2347: 2342: 2338: 2334: 2327: 2319: 2315: 2311: 2307: 2303: 2299: 2295: 2291: 2287: 2280: 2272: 2268: 2264: 2260: 2256: 2252: 2248: 2244: 2237: 2224: 2218: 2214: 2210: 2206: 2202: 2195: 2191: 2181: 2178: 2176: 2173: 2171: 2168: 2166: 2163: 2162: 2156: 2154: 2150: 2146: 2141: 2131: 2127: 2117: 2108: 2106: 2100: 2090: 2088: 2082: 2072: 2070: 2067: 2066:constellation 2063: 2057: 2047: 2045: 2041: 2037: 2028: 2023: 2018: 2008: 2006: 2002: 2001:neutron stars 1998: 1997:visible light 1994: 1988: 1978: 1974: 1964: 1962: 1961:main-sequence 1956: 1941: 1937: 1927: 1925: 1921: 1917: 1913: 1909: 1906: 1905:chromospheric 1902: 1898: 1894: 1886: 1885: 1880: 1876: 1867: 1865: 1861: 1854:Stellar spots 1851: 1837: 1834: 1824: 1816: 1811: 1801: 1799: 1792: 1782: 1777: 1767: 1762: 1749: 1748: 1743: 1740: 1737: 1733: 1730: 1727: 1723: 1719: 1716: 1715: 1714: 1712: 1706: 1696: 1694: 1690: 1686: 1682: 1678: 1674: 1670: 1665: 1660: 1650: 1648: 1642: 1635: 1630: 1621: 1618: 1613: 1611: 1607: 1601: 1599: 1595: 1592:(generally a 1591: 1587: 1583: 1579: 1578: 1573: 1569: 1563: 1552: 1548: 1538: 1533: 1523: 1521: 1517: 1512: 1508: 1502: 1492: 1490: 1486: 1481: 1471: 1469: 1465: 1461: 1457: 1450: 1440: 1438: 1434: 1427: 1417: 1415: 1408: 1398: 1396: 1392: 1388: 1385: 1381: 1375: 1365: 1357: 1355: 1354: 1349: 1348: 1340: 1330: 1328: 1327:T Tauri stars 1324: 1320: 1314: 1304: 1302: 1298: 1292: 1285: 1282: 1278: 1269: 1265: 1255: 1246: 1244: 1233: 1229: 1219: 1217: 1213: 1209: 1205: 1201: 1191: 1189: 1185: 1181: 1180: 1175: 1174: 1169: 1165: 1164: 1159: 1152: 1142: 1140: 1134: 1124: 1122: 1118: 1105: 1099: 1089: 1084: 1074: 1072: 1068: 1064: 1060: 1054: 1044: 1042: 1038: 1034: 1028: 1018: 1014: 1004: 1001: 995: 985: 980: 970: 968: 964: 958: 948: 946: 942: 938: 932: 922: 919: 915: 911: 905: 904:Mira variable 898: 895: 894:Mira variable 891: 887: 878: 874: 864: 859: 849: 844: 834: 832: 831:spectral type 828: 822: 812: 810: 806: 802: 801:Population II 796: 786: 784: 780: 779:Population II 773: 763: 761: 757: 753: 749: 748:Edward Pigott 742: 732: 730: 726: 721: 719: 715: 711: 707: 703: 699: 695: 691: 685: 675: 673: 669: 665: 661: 657: 651: 649: 645: 641: 636: 632: 628: 623: 621: 617: 611: 601: 596: 591: 582: 580: 576: 565: 562: 558: 554: 550: 549: 547: 544: 539: 535: 531: 528: 525: 524: 522: 519: 518: 517: 515: 511: 501: 499: 495: 491: 487: 483: 477: 467: 465: 461: 456: 452: 449: 444: 435: 429: 426: 423: 419: 416: 413: 410: 407: 403: 399: 395: 391: 390: 389: 383: 380: 377: 376: 375: 372: 370: 366: 362: 358: 355: 351: 347: 343: 339: 335: 328: 327:Carina Nebula 324: 319: 310: 308: 304: 294: 292: 287: 285: 281: 280:Cecilia Payne 276: 274: 270: 266: 265:G. D. Maraldi 262: 258: 254: 250: 246: 241: 239: 235: 231: 227: 224:noticed that 223: 218: 216: 212: 208: 204: 194: 192: 188: 184: 176: 172: 169: 166: 163: 162: 161: 159: 155: 151: 147: 146:variable star 139: 135: 130: 120: 117: 109: 106:February 2013 98: 95: 91: 88: 84: 81: 77: 74: 70: 67: – 66: 62: 61:Find sources: 55: 51: 45: 44: 39:This article 37: 33: 28: 27: 22: 21:Variable Star 5740:Solar System 5540:White dwarfs 5530:Brown dwarfs 5513:Most distant 5461:Most massive 5439:Proper names 5399:Photographic 5352:Solar System 5330:observations 5257:Star systems 5216: 5080:Stellar wind 5063:Chromosphere 5036:Oscillations 4916:Helium flash 4766:Hypothetical 4744:X-ray binary 4683:Compact star 4518:Bright giant 4271:Henyey track 4249:Herbig Ae/Be 4136: 4016:Z Andromedae 3998:SW Sextantis 3976:Intermediate 3815:Herbig Ae/Be 3690:SX Phoenicis 3637:cepheid-like 3615: 3554:February 17, 3552:. Retrieved 3538: 3534: 3523:Bibliography 3495: 3491: 3485: 3450: 3446: 3436: 3424:. Retrieved 3414: 3403:. Retrieved 3399: 3390: 3345: 3341: 3331: 3288: 3284: 3278: 3251: 3247: 3237: 3210: 3204: 3171: 3167: 3157: 3130: 3126: 3116: 3099: 3095: 3089: 3064: 3060: 3054: 3031: 2988: 2984: 2978: 2935: 2931: 2925: 2900: 2896: 2890: 2879:. Retrieved 2859: 2855: 2845: 2834:. Retrieved 2822: 2818: 2808: 2797:. Retrieved 2769: 2765: 2755: 2735: 2728: 2717:. Retrieved 2713: 2704: 2692:. Retrieved 2680: 2663: 2659: 2653: 2645:the original 2640: 2630: 2619:. Retrieved 2615: 2606: 2596: 2589: 2570: 2564: 2529: 2525: 2515: 2498:11343/293572 2462: 2458: 2448: 2393: 2389: 2379: 2336: 2332: 2326: 2293: 2289: 2279: 2246: 2242: 2236: 2226:, retrieved 2204: 2194: 2137: 2129: 2114: 2102: 2087:V393 Scorpii 2084: 2059: 2032: 1990: 1976: 1958: 1939: 1890: 1883: 1879:Light curves 1864:chromosphere 1857: 1848: 1830: 1822: 1813: 1798:Z Andromedae 1794: 1779: 1764: 1745: 1735: 1708: 1684: 1680: 1676: 1662: 1644: 1614: 1602: 1590:neutron star 1575: 1565: 1535: 1504: 1483: 1452: 1429: 1410: 1377: 1363: 1351: 1345: 1342: 1316: 1294: 1267: 1252: 1239: 1231: 1197: 1187: 1183: 1177: 1171: 1167: 1161: 1157: 1154: 1136: 1101: 1086: 1056: 1030: 1016: 997: 982: 960: 934: 907: 876: 861: 846: 826: 824: 808: 798: 775: 756:Delta Cephei 744: 725:Delta Cephei 722: 718:Edwin Hubble 716:and beyond. 706:relationship 687: 652: 624: 613: 599: 578: 574: 572: 553:double stars 545: 520: 513: 509: 507: 486:nomenclature 482:R Andromedae 479: 470:Nomenclature 457: 453: 445: 443:brightness. 441: 433: 387: 373: 359: 346:light curves 342:spectroscopy 331: 300: 288: 277: 269:Delta Cephei 242: 226:Omicron Ceti 219: 200: 180: 170: 164: 145: 143: 112: 103: 93: 86: 79: 72: 60: 48:Please help 43:verification 40: 5728:Outer space 5716:Spaceflight 5593:Brown dwarf 5369:Circumpolar 5247:Kraft break 5227:Color index 5202:Metallicity 5162:Designation 5131:Cosmic dust 5053:Photosphere 4819:Dark-energy 4794:Electroweak 4779:Black dwarf 4710:Radio-quiet 4693:White dwarf 4579:White dwarf 4229:Bok globule 4058:BY Draconis 3942:Cataclysmic 3847:supergiants 3782:White dwarf 3751:Semiregular 3738:Long-period 3713:Beta Cephei 3708:Alpha Cygni 3665:BL Herculis 3653:Delta Scuti 3133:: 234–240. 3067:: 215–240. 2991:(2): 1035. 2532:(1): 7–12. 2138:Stars with 2036:binary star 2005:Crab Pulsar 1916:V1794 Cygni 1897:ellipsoidal 1860:solar spots 1736:standstills 1711:white dwarf 1699:Dwarf novae 1617:white dwarf 1582:Crab Nebula 1507:flare stars 1495:Flare stars 1384:hypergiants 1347:V1057 Cygni 1284:V1025 Tauri 1043:pulsators. 1033:V361 Hydrae 967:supergiants 941:supergiants 890:Light curve 783:metallicity 752:Eta Aquilae 729:Beta Cephei 714:Local Group 640:interfering 579:U Geminorum 575:U Geminorum 323:Eta Carinae 307:light curve 263:in 1704 by 191:solar cycle 183:oscillation 5761:Star types 5750:Categories 5555:Candidates 5550:Supernovae 5535:Red dwarfs 5394:Extinction 5182:Kinematics 5177:Luminosity 5155:Properties 5048:Atmosphere 4946:Si burning 4936:Ne burning 4874:White hole 4847:Quasi-star 4774:Blue dwarf 4629:Technetium 4545:Hypergiant 4523:Supergiant 4116:Beta Lyrae 4089:SX Arietis 3955:Dwarf nova 3928:Wolf–Rayet 3845:Giants and 3826:FU Orionis 3669:W Virginis 3426:8 December 3405:2023-12-12 3355:2008.11723 3291:(2): L45. 3174:(7): 837. 2881:2020-04-15 2836:2020-04-15 2799:2020-04-15 2719:2020-04-15 2714:tophat.com 2621:2024-08-10 2539:1808.01862 2472:1709.04634 2403:1601.06990 2228:2023-06-06 2186:References 2165:Guest star 1705:Dwarf nova 1598:black hole 1556:Supernovae 1501:Flare star 1489:equatorial 1258:Protostars 1208:convection 963:red giants 961:These are 945:Betelgeuse 937:red giants 935:These are 914:magnitudes 644:stochastic 620:non-radial 538:supernovae 406:supergiant 402:giant star 398:dwarf star 365:telescopic 334:photometry 273:Beta Lyrae 234:supernovae 211:Betelgeuse 138:Betelgeuse 136:images of 134:VLT-SPHERE 76:newspapers 5704:Astronomy 5486:Brightest 5384:Magnitude 5364:Pole star 5285:Symbiotic 5280:Eclipsing 5212:Starlight 5013:Structure 5003:Supernova 4996:Micronova 4991:Recurrent 4976:Symbiotic 4961:p-process 4956:r-process 4951:s-process 4941:O burning 4931:C burning 4911:CNO cycle 4854:Gravastar 4390:Hypernova 4380:Supernova 4355:Dredge-up 4328:Blue loop 4321:super-AGB 4304:Red clump 4281:Evolution 4239:Protostar 4219:Accretion 4211:Formation 4103:Eclipsing 4003:Symbiotic 3990:Hypernova 3984:Supernova 3864:DY Persei 3803:Protostar 3624:Pulsating 3477:120275241 3382:221340538 3348:(1): 24. 3196:122582479 3001:CiteSeerX 2794:256563765 2772:(2): 65. 2556:119209432 2507:119453488 2371:119191453 2346:1204.6206 2318:162969143 2145:HD 209458 1920:UZ Librae 1689:naked eye 1685:very slow 1562:Supernova 1387:η Carinae 1380:S Doradus 694:resonance 514:extrinsic 510:intrinsic 354:amplitude 253:Chi Cygni 247:in 1669; 238:Aristotle 197:Discovery 5665:Category 5560:Remnants 5456:Extremes 5416:Parallax 5389:Apparent 5379:Asterism 5357:Sunlight 5307:Globular 5292:Multiple 5217:Variable 5207:Rotation 5167:Dynamics 5058:Starspot 4732:Magnetar 4675:Remnants 4491:Subgiant 4464:Subdwarf 4316:post-AGB 4028:Rotating 3795:Eruptive 3680:RR Lyrae 3673:RV Tauri 3633:Cepheids 3039:Archived 3023:40373007 2694:15 April 2440:26679699 2390:PLOS ONE 2271:54697141 2159:See also 1999:. These 1833:sunspots 1606:SN 1987A 1520:Wolf 359 1460:nitrogen 1173:V777 Her 1059:hydrogen 660:pressure 656:acoustic 635:overtone 631:harmonic 498:RR Lyrae 460:cepheids 408:, etc.)? 303:spectrum 261:R Hydrae 257:G. Kirch 5690:Portals 5632:Gravity 5581:Related 5501:Nearest 5449:Chinese 5297:Cluster 5270:Contact 5107:Proplyd 4981:Remnant 4869:Blitzar 4843:Hawking 4799:Strange 4749:Burster 4705:Neutron 4658:Extreme 4609:He-weak 4254:T Tauri 3833:T Tauri 3660:Type II 3500:Bibcode 3498:: 764. 3455:Bibcode 3360:Bibcode 3323:9481357 3303:Bibcode 3256:Bibcode 3215:Bibcode 3176:Bibcode 3135:Bibcode 3104:Bibcode 3102:: 196. 3069:Bibcode 2993:Bibcode 2970:2445038 2950:Bibcode 2905:Bibcode 2864:Bibcode 2862:: 487. 2827:Bibcode 2774:Bibcode 2668:Bibcode 2666:: 266. 2477:Bibcode 2431:4683080 2408:Bibcode 2351:Bibcode 2298:Bibcode 2251:Bibcode 2140:planets 2105:Sheliak 2069:Perseus 2064:in the 2040:eclipse 1993:pulsars 1893:equator 1608:in the 1596:) or a 1511:UV Ceti 1391:P Cygni 1356:stars. 1353:T Tauri 1323:T Tauri 1190:stars. 1163:ZZ Ceti 897:χ Cygni 668:gravity 259:, then 215:Antares 90:scholar 5622:Galaxy 5610:Planet 5598:Desert 5506:bright 5444:Arabic 5265:Binary 5085:Bubble 4809:Planck 4784:Exotic 4720:Binary 4715:Pulsar 4653:Helium 4614:Barium 4557:Carbon 4550:Yellow 4538:Yellow 4511:Yellow 4350:PG1159 4084:Pulsar 3644:Type I 3475: 3380: 3321: 3225: 3194: 3021: 3003: 2968: 2792: 2743: 2577: 2554: 2505: 2438: 2428: 2369: 2316: 2269: 2219: 1987:Pulsar 1912:FK Com 1726:Cygnus 1594:pulsar 1568:galaxy 1468:oxygen 1464:carbon 1456:helium 1299:mass) 1179:GW Vir 1121:Cygnus 1067:helium 1063:carbon 1041:p-mode 672:g-mode 664:p-mode 616:radial 567:shape. 464:helium 350:period 92: 85: 78: 71: 63: 5627:Guest 5431:Lists 5312:Super 4966:Fusor 4839:Black 4824:Quark 4804:Preon 4789:Boson 4725:X-ray 4641:Shell 4594:Ap/Bp 4496:Giant 4414:Early 4360:OH/IR 4190:Stars 4111:Algol 3970:Polar 3913:Flare 3906:Other 3820:Orion 3765:Other 3473:S2CID 3378:S2CID 3350:arXiv 3319:S2CID 3293:arXiv 3192:S2CID 3047:AAVSO 3019:S2CID 2966:S2CID 2940:arXiv 2825:: 3. 2790:S2CID 2689:(PDF) 2552:S2CID 2534:arXiv 2503:S2CID 2467:arXiv 2398:arXiv 2367:S2CID 2341:arXiv 2314:S2CID 2267:S2CID 2062:Algol 2044:Algol 1664:Novae 1653:Novae 1647:novae 1586:China 1297:solar 1170:, or 1160:, or 1117:Deneb 561:Earth 534:novae 494:Bayer 203:Algol 156:(its 154:Earth 148:is a 97:JSTOR 83:books 5302:Open 5197:Mass 5021:Core 4971:Nova 4864:Iron 4814:Dark 4624:Lead 4604:HgMn 4599:CEMP 4528:Blue 4501:Blue 4419:Late 4201:List 4150:List 3965:Nova 3805:and 3746:Mira 3556:2023 3428:2021 3223:ISBN 2741:ISBN 2696:2020 2575:ISBN 2436:PMID 2217:ISBN 2147:and 2025:How 1991:Few 1918:and 1884:TESS 1681:slow 1677:fast 1659:Nova 1549:and 1518:and 1466:and 1389:and 1243:TESS 1198:The 1188:PNNV 1186:and 1110:to A 1065:and 918:Mira 536:and 340:and 271:and 213:and 150:star 69:news 5603:Sub 5337:Sun 4756:SGR 4533:Red 4506:Red 3807:PMS 3635:and 3543:doi 3508:doi 3496:329 3463:doi 3451:467 3368:doi 3346:902 3311:doi 3289:426 3264:doi 3252:171 3184:doi 3143:doi 3131:150 3100:259 3077:doi 3011:doi 2989:584 2958:doi 2936:660 2913:doi 2872:doi 2860:138 2782:doi 2544:doi 2493:hdl 2485:doi 2426:PMC 2416:doi 2359:doi 2337:773 2306:doi 2259:doi 2247:125 2209:doi 1683:or 1200:Sun 1184:DOV 1168:DBV 1158:DAV 965:or 939:or 892:of 658:or 633:or 555:or 512:or 187:Sun 52:by 5752:: 4636:Be 4589:Am 4572:CH 4567:CN 4486:OB 4481:WR 4148:* 3671:, 3667:, 3651:, 3539:90 3537:. 3533:. 3506:. 3494:. 3471:. 3461:. 3449:. 3445:. 3398:. 3376:. 3366:. 3358:. 3344:. 3340:. 3317:. 3309:. 3301:. 3287:. 3262:. 3250:. 3246:. 3221:. 3213:. 3190:. 3182:. 3172:53 3170:. 3166:. 3141:. 3129:. 3125:. 3098:. 3075:. 3065:16 3063:. 3017:. 3009:. 2999:. 2987:. 2964:. 2956:. 2948:. 2934:. 2911:. 2901:12 2899:. 2870:. 2858:. 2854:. 2823:28 2821:. 2817:. 2788:. 2780:. 2768:. 2764:. 2712:. 2664:14 2662:. 2639:. 2614:. 2550:. 2542:. 2530:21 2528:. 2524:. 2501:. 2491:. 2483:. 2475:. 2463:29 2461:. 2457:. 2434:. 2424:. 2414:. 2406:. 2394:10 2392:. 2388:. 2365:. 2357:. 2349:. 2335:. 2312:. 2304:. 2294:18 2292:. 2288:. 2265:. 2257:. 2245:. 2215:, 2203:, 2155:. 2089:. 2071:. 2007:. 1926:. 1914:, 1800:. 1679:, 1612:. 1600:. 1522:. 1462:, 1458:, 1416:. 1218:. 1112:ep 1108:ep 1073:. 731:. 650:. 581:. 516:. 404:, 400:, 336:, 205:. 193:. 144:A 5692:: 4829:Q 4648:B 4562:S 4474:B 4469:O 4457:M 4452:K 4447:G 4442:F 4437:A 4432:B 4427:O 4182:e 4175:t 4168:v 3866:) 3862:( 3675:) 3663:( 3655:) 3647:( 3608:e 3601:t 3594:v 3558:. 3545:: 3514:. 3510:: 3502:: 3479:. 3465:: 3457:: 3430:. 3408:. 3384:. 3370:: 3362:: 3352:: 3325:. 3313:: 3305:: 3295:: 3272:. 3266:: 3258:: 3231:. 3217:: 3198:. 3186:: 3178:: 3151:. 3145:: 3137:: 3110:. 3106:: 3083:. 3079:: 3071:: 3025:. 3013:: 2995:: 2972:. 2960:: 2952:: 2942:: 2919:. 2915:: 2907:: 2884:. 2874:: 2866:: 2839:. 2829:: 2802:. 2784:: 2776:: 2770:7 2749:. 2722:. 2698:. 2674:. 2670:: 2624:. 2583:. 2558:. 2546:: 2536:: 2509:. 2495:: 2487:: 2479:: 2469:: 2442:. 2418:: 2410:: 2400:: 2373:. 2361:: 2353:: 2343:: 2320:. 2308:: 2300:: 2273:. 2261:: 2253:: 2211:: 1667:( 1106:B 540:. 424:) 396:( 177:. 119:) 113:( 108:) 104:( 94:· 87:· 80:· 73:· 46:. 23:.

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

Index