Variable star - Knowledge (XXG)

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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.

5722: 1886: 5746: 601: 5710: 5734: 1404:. 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 5683: 4151: 140: 466:

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.

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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.

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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

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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

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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.

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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

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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

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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

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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

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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

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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

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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.

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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

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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

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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

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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

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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

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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.

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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.

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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.

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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

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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.

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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.

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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.

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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

822:. 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. 1354:

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.

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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

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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.

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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

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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

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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

840:. 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 958:, 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. 858:

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.

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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

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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.

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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

511:. 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. 873:

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.

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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

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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,

954:. 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 1264:

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.

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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

1498:(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 1731:, 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 1287: 1050:. 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 2342:

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?".

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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

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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

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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

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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

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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) (

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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.

171:) 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: 1279:

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.

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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

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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.

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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

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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

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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)

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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

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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.

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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.

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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

534:: 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. 1068:

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

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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

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

297:. Her analyses and observations of variable stars, carried out with her husband, Sergei Gaposchkin, laid the basis for all subsequent work on the subject. 2720: 1028:

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

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

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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)?

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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.

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

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

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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

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

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

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

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

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

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

304:(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. 293:

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

184:, whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star 2696: 422:

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)

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

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

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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.

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

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

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

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

1542: 79: 5700: 5565: 5516: 5491: 4784: 3728: 1023: 559:: stars where the variability is caused by external properties like rotation or eclipses. There are two main subgroups. 500: 441:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

239:(later named Mira) pulsated in a cycle taking 11 months; the star had previously been described as a nova by 5766: 5496: 5046: 4956: 4898: 4824: 4395: 4321: 3933: 3787: 3766: 2079: 1561: 1222: 967: 920: 328: 4271: 574:'s vantage point the stars occasionally eclipse one another as they orbit, or the planet eclipses its star. 5657: 5637: 5409: 5404: 5197: 5146: 4951: 4941: 4614: 4412: 4380: 4254: 4160: 3864: 3817: 3813: 3782: 3733: 3349:"Short Term Variability of Evolved Massive Stars with TESS II: A New Class of Cool, Pulsating Supergiants" 3011: 2185: 2175: 2032: 1736: 1620: 1384: 1143: 1131: 1063: 841: 720: 344: 217: 75: 2211: 5511: 5481: 5476: 5466: 5394: 5182: 4348: 4008: 3792: 3700: 2994:

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

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

3255:"Mapping the Instability Domains of GW Vir Stars in the Effective Temperature-Surface Gravity Diagram" 228:, incorporating these brightness changes into narratives that are passed down through oral tradition. 5652: 5550: 5540: 5389: 5357: 5151: 4946: 4931: 4244: 4068: 3723: 3718: 3675: 3663: 3510: 3501:

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

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

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

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

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

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

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

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

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

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

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

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

923:(AGB) red giants. Over periods of many months they fade and brighten by between 2.5 and 11 636:

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

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

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

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

507:. Letters RR through RZ, SS through SZ, up to ZZ are used for the next discoveries, e.g. 3514: 3374: 3270: 3229: 3190: 3149: 3118: 3091: 3007: 2964: 2919: 2878: 2841: 2788: 2682: 2491: 2422: 2365: 2312: 2265: 5675: 5441: 5280: 5107: 5078: 5053: 4986: 4675: 4543: 4429: 4331: 4221: 4211: 4121: 4019: 3830: 3654: 2606: 2441: 2396: 2223: 2163: 2066: 1934: 1323: 1114: 977: 951: 770: 712: 457:

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

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

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

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

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

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

995:

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

5687: 5362: 5312: 5307: 5207: 5090: 5073: 5031: 4991: 4926: 4809: 4754: 4735: 4715: 4693: 4685: 4528: 4521: 4360: 4281: 4264: 3980: 3843: 3590: 3333: 3047:

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

2980: 2011: 1915: 1874: 1808: 1600: 1363: 1337: 1333: 766: 735: 728: 682: 492: 352: 279: 236: 3585: 3325: 3046: 2721:"OpenStax: Astronomy | 19.3 Variable Stars: One Key to Cosmic Distances | Top Hat" 1148:

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

3478: 3453: 2927: 2431: 2297:"Evidence of Periodicity in Ancient Egyptian Calendars of Lucky and Unlucky Days" 5603: 5302: 5275: 5267: 5257: 5237: 5212: 5141: 5063: 4819: 4794: 4789: 4703: 4663: 4624: 4589: 4572: 4567: 4239: 4155: 4113: 2941:

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

2533:"Yes, Aboriginal Australians can and did discover the variability of Betelgeuse" 2114:

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

2046: 2027: 2015: 1926: 1907: 1889: 1721: 1627: 1592: 1397: 1357: 1051: 1043: 900: 793: 762: 739: 724: 674: 563: 356: 333: 317: 201: 193: 42: 3383: 3348: 389:

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

231:

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

5187: 4884: 4857: 4834: 4814: 4799: 4651: 4555: 4533: 4511: 4506: 4370: 3965: 3923: 2320: 2273: 2115: 1885: 1715: 1608: 1517: 1511: 1394: 1314:

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

1218: 973: 955: 947: 907: 654: 416: 412: 408: 283: 254:

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

221: 148: 144: 17: 2611:. Osmania University, Digital Library Of India. McGraw Hill Book Company Inc. 814:, but of lower mass than type II Cepheids. Due to their common occurrence in 5374: 5222: 5006: 4971: 4966: 4961: 4921: 4874: 4864: 4658: 4634: 4609: 4516: 4467: 4400: 4390: 4365: 4338: 4314: 4249: 4000: 3994: 3558: 2155: 1699: 1572: 1390: 704: 666: 548: 375: 364: 360: 278:. By 1786, ten variable stars were known. John Goodricke himself discovered 263: 248: 244: 2450: 699:

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

5367: 5068: 4742: 4501: 4474: 3308: 2955: 1870: 1616: 1530: 1470: 1187:, stars, with helium-dominated atmospheres and the spectral type DB; and 1183: 1069: 685:. Pulsating variable stars typically pulsate in only one of these modes. 670: 645: 641: 508: 271: 2508: 355:. Measurements of their changes in brightness can be plotted to produce 5642: 5117: 4879: 4646: 4599: 4582: 4577: 4496: 3158: 3133: 2499: 2050: 1903: 1843: 1761:. These binary systems usually have orbital periods of under 2.5 hours. 1521: 1499: 1401: 1177:, stars, with hydrogen-dominated atmospheres and the spectral type DA; 1173: 1113:

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

678: 600: 225: 5632: 5620: 4839: 4725: 4094: 2003: 1997: 1604: 1578: 1478: 1474: 1466: 1189: 1077: 1073: 703:, that swell and shrink very regularly caused by the star's own mass 640:

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

474: 2466:"Observations of red-giant variable stars by Aboriginal Australians" 1755:, which undergo both frequent small outbursts, and rarer but larger 792:

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

657:. The study of stellar interiors using their pulsations is known as 438:

strong magnetic fields on the star betray themselves in the spectrum

139: 5682: 4150: 3522: 3365: 3279: 3254: 3025: 2972: 2886: 2549: 2482: 2413: 2296: 1706:

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

3057: 2356: 2072: 2054: 2031: 1884: 1657: 1638: 1596: 1286: 1127: 895: 599: 571: 327: 213: 164: 138: 3595: 3454:"Long-term photometric study of FK Comae Berenices and HD 199178" 633:, where one part of the star expands while another part shrinks. 5001: 4981: 4200: 3975: 2252:

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

1674: 1669: 1253: 928: 738:, while a completely separate class of variables is named after 544: 160: 4173: 3599: 3407:"Rotating Variables: Mapping the Surfaces of the Stars | aavso" 2162:, and all of the planets and planet candidates detected by the 5347: 1307: 1210: 197: 36: 3107:

Radial and Nonradial Pulsations as Probes of Stellar Physics

1902:

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

629:, where the entire star expands and shrinks as a whole; and 1698:, depending on the behaviour of their light curve. Several 473:

is known to be driven by oscillations in the ionization of

1749:

are seen, part way between maximum and minimum brightness.

611:

Examples of types within these divisions are given below.

2210:

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

262:

gave the correct explanation of its variability in 1784.

4169: 3542:"Irregularities of Period of Long Period Variable Stars" 3431:"MAST: Barbara A. Mikulski Archive for Space Telescopes" 1910:

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

3580: 1217:. Oscillations in the Sun are driven stochastically by 990:

Long-period variable star § Long secondary periods

1626:

A supernova may also result from mass transfer onto a

403:

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

5698: 3591:

Society for Popular Astronomy – Variable Star Section

385:

From the light curve the following data are derived:

3134:"Pulsating Hot Subdwarfs -- an Observational Review" 1745:, in which occasional plateaux of brightness called 588:

stars after the first recognized star in the class,

200:, for example, varies by about 0.1% over an 11-year 186:

has an orbiting companion that sometimes eclipses it

27:

Star whose brightness fluctuates, as seen from Earth

5591: 5440: 5338: 5266: 5165: 5022: 4897: 4775: 4684: 4411: 4290: 4220: 4112: 4082: 4061: 4045: 4038: 3951: 3916: 3890: 3855: 3812: 3805: 3775: 3747: 3709: 3642: 3633: 3581:

The American Association of Variable Star Observers

3253:Quirion, P.-O.; Fontaine, G.; Brassard, P. (2007). 1615:One of the most studied supernovae of this type is 220:are also known to have observed the variability of 67:. Unsourced material may be challenged and removed. 1643:Images showing the expansion of the light echo of 1595:, left over from a supernova that was observed in 399:From the spectrum the following data are derived: 392:what is the period of the brightness fluctuations? 4073: 3546:Monthly Notices of the Royal Astronomical Society 1502:regions caused by the rapid rotational velocity. 192:Many, possibly most, stars exhibit at least some 1009:Beta Cephei (β Cep) variables (sometimes called 927:, a 6 fold to 30,000 fold change in luminosity. 2697:"Variable Star Classification and Light Curves" 2212:"Chapter 7 - Nonlocal Theory of Variable Stars" 1591:. A well-known example of such a nebula is the 380:American Association of Variable Star Observers 2652:Contributions of 20th Century Women to Physics 2049:. When seen from certain angles, one star may 1970:Alpha Canum Venaticorum (α CVn) variables are 1682:) accelerates explosively. They form in close 4185: 3611: 2584:. Sydney: Allen and Unwin. pp. 144–166. 1032:Very rapidly pulsating hot (subdwarf B) stars 8: 2830:Aerodynamic Phenomena in Stellar Atmospheres 2777:Journal of Astronomical History and Heritage 2537:Journal of Astronomical History and Heritage 343:Variable stars are generally analysed using 3259:The Astrophysical Journal Supplement Series 3072:Annual Review of Astronomy and Astrophysics 4417: 4192: 4178: 4170: 4042: 3809: 3639: 3618: 3604: 3596: 3222:Encyclopedia of Astronomy and Astrophysics 3557: 3477: 3382: 3364: 3307: 3278: 3157: 3015: 2954: 2548: 2507: 2481: 2440: 2430: 2412: 2355: 1720:Dwarf novae are double stars involving a 677:. In other cases, the restoring force is 127:Learn how and when to remove this message 1408:, and may be a different type of event. 196:in luminosity: the energy output of the 5705: 2744:Burnell, S. Jocelyn Bell (2004-02-26). 2202: 1552:Cataclysmic or explosive variable stars 818:, they are occasionally referred to as 243:in 1596. This discovery, combined with 3540:Eddington, A.S.; Plakidis, S. (1929). 3175:"REVIEW: Physics of white dwarf stars" 2470:The Australian Journal of Anthropology 2028:Binary star § Eclipsing binaries 1423:timescale. The best known example is 1239:BLAP (Blue Large-Amplitude Pulsators) 7: 3452:Panov, K.; Dimitrov, D. (May 2007). 2747:An Introduction to the Sun and Stars 1042:The prototype of this rare class is 65:adding citations to reliable sources 3433:. Space Telescope Science Institute 3173:Koester, D.; Chanmugam, G. (1990). 3092:10.1146/annurev.aa.16.090178.001243 689:Cepheids and cepheid-like variables 302:General Catalogue of Variable Stars 3138:Communications in Asteroseismology 2224:10.1016/b978-0-444-64019-2.00007-7 1080:lines are extra strong, a type of 673:mode of pulsation, abbreviated to 25: 2797:10.3724/SP.J.1440-2807.2004.02.01 2648:"Cecilia Helena Payne-Gaposchkin" 2559:10.3724/SP.J.1440-2807.2018.01.02 1966:Alpha2 Canum Venaticorum variable 1960:Alpha Canum Venaticorum variables 1787:Polar (cataclysmic variable star) 1306:Variability of more massive (2–8 1247:Fast yellow pulsating supergiants 5744: 5732: 5720: 5708: 5681: 5671: 5670: 4149: 2671:Odessa Astronomical Publications 2395:Jetsu, L.; Porceddu, S. (2015). 2301:Cambridge Archaeological Journal 1134:is the prototype of this class. 1038:Subdwarf B star § Variables 863:Rapidly oscillating Ap variables 734:The Cepheids are named only for 604:Intrinsic variable types in the 477:(from He to He and back to He). 41: 1446:(R CrB) is the prototype star. 1328:Orion variables are young, hot 984:Long secondary period variables 769:, discovered to be variable by 52:needs additional citations for 3179:Reports on Progress in Physics 2863:"1963ApJ...138..487C Page 487" 2750:. Cambridge University Press. 2218:, Elsevier, pp. 321–377, 1537:RS Canum Venaticorum variables 1221:in its outer layers. The term 844:is usually between A0 and F5. 449:Interpretation of observations 163:whose brightness as seen from 1: 5583:Timeline of stellar astronomy 3739:Blue large-amplitude pulsator 2773:"2004JAHH....7...65M Page 65" 1543:RS Canum Venaticorum variable 1018:Slowly pulsating B-type stars 519:Variable stars may be either 359:. For regular variables, the 3060:. Accessed October 2, 2008. 2928:10.1016/j.newast.2007.04.002 2826:"1967IAUS...28....3C Page 3" 2646:Turner, J (March 16, 2001). 2608:The Stars Of High Luminosity 2432:10.1371/journal.pone.0144140 1881:FK Comae Berenices variables 1431:R Coronae Borealis variables 1024:Slowly pulsating B-type star 761:detected the variability of 332:A photogenic variable star, 5243:Hertzsprung–Russell diagram 3326:10.1051/0004-6361:200400079 1485:Gamma Cassiopeiae variables 1437:R Coronae Borealis variable 869:Rapidly oscillating Ap star 746:Classical Cepheid variables 606:Hertzsprung–Russell diagram 5793: 5157:Kelvin–Helmholtz mechanism 3479:10.1051/0004-6361:20065596 3458:Astronomy and Astrophysics 3296:Astronomy and Astrophysics 3199:10.1088/0034-4885/53/7/001 2605:Payne, Cecilia H. (1930). 2134: 2107: 2089: 2064: 2057:, or Beta Persei (β Per). 2025: 1995: 1992:Optically variable pulsars 1981: 1963: 1944: 1941:BY Draconis variable stars 1818: 1799: 1784: 1769: 1713: 1702:novae have been recorded, 1667: 1649: 1570: 1555: 1540: 1509: 1491:Gamma Cassiopeiae variable 1488: 1457: 1434: 1415: 1382: 1347: 1336:variables. Variability of 1321: 1299: 1272: 1236: 1159: 1141: 1130:, in the constellation of 1106: 1091: 1061: 1035: 1021: 1002: 987: 965: 939: 912: 881: 866: 851: 829: 803: 780: 752:Classical Cepheid variable 749: 692: 618: 484: 324:Variable star observations 300:The latest edition of the 266:was identified in 1686 by 29: 5666: 4420: 4207: 4145: 3353:The Astrophysical Journal 2996:The Astrophysical Journal 2943:The Astrophysical Journal 2867:The Astrophysical Journal 2374:10.1088/0004-637X/773/1/1 2344:The Astrophysical Journal 2321:10.1017/S0959774308000395 2274:10.1007/s11214-006-9046-5 2131:W Ursae Majoris variables 2086:Double Periodic variables 1821:AM Canum Venaticorum star 1558:Cataclysmic variable star 487:Variable star designation 5536:With multiple exoplanets 3552:(1). London, UK: 65–71. 3384:10.3847/1538-4357/abb318 2407:(12): e.0144140 (23pp). 2137:W Ursae Majoris variable 2092:Double periodic variable 1914:G and K and show strong 1830:Extrinsic variable stars 1072:while on the other hand 962:Slow irregular variables 615:Pulsating variable stars 596:Intrinsic variable stars 557:Extrinsic variable stars 532:Intrinsic variable stars 459:Arthur Stanley Eddington 289:In 1930, astrophysicist 4322:Asymptotic giant branch 3788:Solar-like oscillations 3729:Slowly pulsating B-type 3470:2007A&A...467..229P 3318:2004A&A...426L..45N 3084:1978ARA&A..16..215L 2580:Hamacher, D.W. (2022). 2531:Schaefer, B.E. (2018). 2464:Hamacher, D.W. (2018). 1838:Rotating variable stars 1562:Symbiotic variable star 1379:Luminous blue variables 1330:pre–main-sequence stars 1260:Eruptive variable stars 1223:solar-like oscillations 1205:Solar-like oscillations 1138:Gamma Doradus variables 1058:PV Telescopii variables 968:Slow irregular variable 921:Asymptotic giant branch 501:Friedrich W. Argelander 5658:Tidal disruption event 5147:Circumstellar envelope 4381:Luminous blue variable 3865:Luminous blue variable 3696:Rapidly oscillating Ap 3586:GCVS Variability Types 2186:List of variable stars 2041: 2006:have been detected in 1899: 1796:Z Andromedae variables 1753:SU Ursae Majoris stars 1743:Z Camelopardalis stars 1735:after the variable in 1647: 1621:Large Magellanic Cloud 1385:Luminous blue variable 1371:Giants and supergiants 1297: 1275:Pre–main-sequence star 1156:Pulsating white dwarfs 1144:Gamma Doradus variable 1064:PV Telescopii variable 910: 848:SX Phoenicis variables 608: 340: 218:Aboriginal Australians 152: 5777:Concepts in astronomy 5183:Effective temperature 3559:10.1093/mnras/90.1.65 3503:Astrophysical Journal 3220:Murdin, Paul (2002). 3132:Kilkenny, D. (2007). 2861:Cox, John P. (1963). 2771:Mestel, Leon (2004). 2582:The First Astronomers 2254:Space Science Reviews 2216:Nonlocal Astrophysics 2122:W Serpentis variables 2035: 1888: 1856:Ellipsoidal variables 1802:Z Andromedae variable 1781:AM Herculis variables 1766:DQ Herculis variables 1642: 1290: 1162:Pulsating white dwarf 1103:Alpha Cygni variables 999:Beta Cephei variables 936:Semiregular variables 899: 878:Long period variables 854:SX Phoenicis variable 826:Delta Scuti variables 709:fundamental frequency 681:and this is called a 638:fundamental frequency 603: 363:of variation and its 331: 308:Detecting variability 142: 5653:Planet-hosting stars 5531:With resolved images 5502:Historical brightest 5432:Photometric-standard 5358:Solar radio emission 5152:Eddington luminosity 4932:Triple-alpha process 4870:Thorne–Żytkow object 4245:Young stellar object 4053:Rotating ellipsoidal 3961:AM Canum Venaticorum 3908:RS Canum Venaticorum 2658:on October 12, 2012. 2104:Beta Lyrae variables 1978:SX Arietis variables 1947:BY Draconis variable 1842:Stars with sizeable 1520:, also known as the 1454:Wolf–Rayet variables 1344:FU Orionis variables 1109:Alpha Cygni variable 1005:Beta Cephei variable 942:Semiregular variable 884:Long period variable 832:Delta Scuti variable 773:a few months later. 570:where, as seen from 562:Eclipsing binaries, 61:improve this article 5477:Highest temperature 5248:Color–color diagram 5113:Protoplanetary disk 4917:Proton–proton chain 4595:Chemically peculiar 4090:α Canum Venaticorum 3515:1988ApJ...329..764L 3375:2020ApJ...902...24D 3271:2007ApJS..171..219Q 3230:2002eaa..book.....M 3191:1990RPPh...53..837K 3150:2007CoAst.150..234K 3119:2002ASPC..259..196D 3008:2003ApJ...584.1035O 2965:2007ApJ...660.1486S 2920:2007NewA...12..556M 2879:1963ApJ...138..487C 2842:1967IAUS...28....3C 2824:Cox, J. P. (1967). 2789:2004JAHH....7...65M 2683:2001OAP....14..266S 2492:2018AuJAn..29...89H 2423:2015PLoSO..1044140J 2366:2013ApJ...773....1J 2313:2008CArcJ..18..327P 2266:2006SSRv..125...53F 2110:Beta Lyrae variable 1984:SX Arietis variable 1851:Non-spherical stars 1583:Chandrasekhar limit 1448:DY Persei variables 1406:supernova impostors 1082:Extreme helium star 1046:, a 15th magnitude 919:Mira variables are 707:, generally by the 372:Amateur astronomers 256:Geminiano Montanari 182:Extrinsic variables 176:Intrinsic variables 30:For the novel, see 5482:Lowest temperature 5233:Photometric system 5203:Absolute magnitude 5137:Circumstellar dust 4750:Stellar black hole 4386:Stellar population 4272:Herbig–Haro object 4074:FK Comae Berenices 3870:R Coronae Borealis 3660:Classical cepheids 3159:10.1553/cia150s234 3052:2010-06-15 at the 2627:www.britannica.com 2500:10.1111/taja.12257 2181:Irregular variable 2145:Planetary transits 2042: 2040:vary in brightness 2038:eclipsing binaries 2022:Eclipsing binaries 1906:); hence they are 1900: 1772:Intermediate polar 1733:SS Cygni variables 1648: 1588:supernova remnants 1444:R Coronae Borealis 1412:Yellow hypergiants 1389:Also known as the 1312:Herbig Ae/Be stars 1302:Herbig Ae/Be stars 1298: 1283:Herbig Ae/Be stars 1088:RV Tauri variables 1011:Beta Canis Majoris 911: 800:RR Lyrae variables 609: 341: 336:, embedded in the 169:apparent magnitude 153: 5696: 5695: 5599:Substellar object 5578:Planetary nebulae 4997:Luminous red nova 4907:Deuterium burning 4893: 4892: 4376:Instability strip 4356:Wolf-Rayet nebula 4310:Horizontal branch 4255:Pre-main-sequence 4167: 4166: 4132:Planetary transit 4108: 4107: 4029: 4022: 4003: 3989: 3971:Luminous red nova 3947: 3946: 3929:Gamma Cassiopeiae 3882:Yellow hypergiant 3878: 3846: 3839: 3801: 3800: 3687: 3667: 2757:978-0-521-54622-5 2233:978-0-444-64019-2 2191:Stellar pulsation 1729:U Geminorum stars 1680:degenerate matter 1652:Luminous red nova 1635:Luminous red nova 1496:Gamma Cassiopeiae 1418:Yellow hypergiant 1292:Herbig Ae/Be star 1094:RV Tauri variable 816:globular clusters 806:RR Lyrae variable 721:Henrietta Leavitt 701:instability strip 621:Stellar pulsation 568:planetary systems 499:was developed by 495:. This system of 469:The pulsation of 349:spectrophotometry 295:Cepheid variables 233:Johannes Holwarda 137: 136: 129: 111: 16:(Redirected from 5784: 5749: 5748: 5747: 5737: 5736: 5735: 5725: 5724: 5723: 5713: 5712: 5711: 5704: 5688:Stars portal 5686: 5685: 5674: 5673: 5330:Planetary system 5253:Strömgren sphere 5125:Asteroseismology 4846:Black hole star 4418: 4344:Planetary nebula 4305:Red-giant branch 4194: 4187: 4180: 4171: 4154: 4153: 4043: 4025: 4018: 3999: 3985: 3903:FS Canis Majoris 3872: 3842: 3835: 3810: 3673: 3657: 3640: 3620: 3613: 3606: 3597: 3570: 3568: 3566: 3561: 3527: 3526: 3498: 3492: 3491: 3481: 3449: 3443: 3442: 3440: 3438: 3427: 3421: 3420: 3418: 3417: 3403: 3397: 3396: 3386: 3368: 3344: 3338: 3337: 3311: 3309:astro-ph/0409243 3291: 3285: 3284: 3282: 3250: 3244: 3243: 3217: 3211: 3210: 3170: 3164: 3163: 3161: 3129: 3123: 3122: 3102: 3096: 3095: 3067: 3061: 3044: 3038: 3037: 3019: 2991: 2985: 2984: 2958: 2956:astro-ph/0701463 2949:(2): 1486–1491. 2938: 2932: 2931: 2903: 2897: 2896: 2894: 2893: 2858: 2852: 2851: 2849: 2848: 2821: 2815: 2814: 2812: 2811: 2768: 2762: 2761: 2741: 2735: 2734: 2732: 2731: 2717: 2711: 2710: 2708: 2706: 2701: 2693: 2687: 2686: 2666: 2660: 2659: 2654:. Archived from 2643: 2637: 2636: 2634: 2633: 2619: 2613: 2612: 2602: 2596: 2595: 2577: 2571: 2570: 2552: 2528: 2522: 2521: 2511: 2485: 2461: 2455: 2454: 2444: 2434: 2416: 2392: 2386: 2385: 2359: 2350:(1): A1 (14pp). 2339: 2333: 2332: 2292: 2286: 2285: 2249: 2243: 2242: 2241: 2240: 2207: 1935:(contact) binary 1815:AM CVn variables 1645:V838 Monocerotis 1527:Proxima Centauri 1227:asteroseismology 1150:spectral classes 1115:spectral classes 820:cluster Cepheids 783:Type II Cepheids 777:Type II Cepheids 711:. Generally the 695:Cepheid variable 659:asteroseismology 405:luminosity class 132: 125: 121: 118: 112: 110: 69: 45: 37: 21: 5792: 5791: 5787: 5786: 5785: 5783: 5782: 5781: 5757: 5756: 5755: 5745: 5743: 5733: 5731: 5721: 5719: 5709: 5707: 5699: 5697: 5692: 5680: 5662: 5587: 5556:Milky Way novae 5492:Smallest volume 5436: 5417:Radial velocity 5340: 5334: 5286:Common envelope 5262: 5161: 5130:Helioseismology 5101:Bipolar outflow 5042:Microturbulence 5037:Convection zone 5018: 4912:Lithium burning 4899:Nucleosynthesis 4889: 4771: 4680: 4407: 4286: 4235:Molecular cloud 4216: 4203: 4198: 4168: 4163: 4156:Star portal 4148: 4141: 4137:W Ursae Majoris 4104: 4083:Magnetic fields 4078: 4057: 4034: 3943: 3912: 3898:Double periodic 3891:Eruptive binary 3886: 3857: 3851: 3797: 3771: 3743: 3711: 3710:Blue-white with 3705: 3647: 3629: 3624: 3577: 3564: 3562: 3539: 3536: 3531: 3530: 3500: 3499: 3495: 3451: 3450: 3446: 3436: 3434: 3429: 3428: 3424: 3415: 3413: 3405: 3404: 3400: 3346: 3345: 3341: 3293: 3292: 3288: 3252: 3251: 3247: 3240: 3219: 3218: 3214: 3172: 3171: 3167: 3131: 3130: 3126: 3104: 3103: 3099: 3069: 3068: 3064: 3054:Wayback Machine 3045: 3041: 3017:10.1.1.514.3679 2993: 2992: 2988: 2940: 2939: 2935: 2905: 2904: 2900: 2891: 2889: 2860: 2859: 2855: 2846: 2844: 2823: 2822: 2818: 2809: 2807: 2770: 2769: 2765: 2758: 2743: 2742: 2738: 2729: 2727: 2719: 2718: 2714: 2704: 2702: 2699: 2695: 2694: 2690: 2668: 2667: 2663: 2645: 2644: 2640: 2631: 2629: 2621: 2620: 2616: 2604: 2603: 2599: 2592: 2579: 2578: 2574: 2530: 2529: 2525: 2463: 2462: 2458: 2394: 2393: 2389: 2341: 2340: 2336: 2294: 2293: 2289: 2251: 2250: 2246: 2238: 2236: 2234: 2209: 2208: 2204: 2199: 2172: 2160:GSC 02652-01324 2147: 2139: 2133: 2124: 2112: 2106: 2094: 2088: 2069: 2063: 2061:Algol variables 2030: 2024: 2000: 1994: 1986: 1980: 1968: 1962: 1957: 1955:Magnetic fields 1949: 1943: 1921:. Examples are 1883: 1867: 1858: 1853: 1840: 1832: 1823: 1817: 1804: 1798: 1789: 1783: 1774: 1768: 1718: 1712: 1704:Nova Cygni 1975 1672: 1666: 1654: 1637: 1575: 1569: 1564: 1556:Main articles: 1554: 1545: 1539: 1514: 1508: 1493: 1487: 1462: 1460:Wolf–Rayet star 1456: 1439: 1433: 1425:Rho Cassiopeiae 1420: 1414: 1387: 1381: 1373: 1352: 1350:FU Orionis star 1346: 1326: 1320: 1318:Orion variables 1304: 1285: 1277: 1271: 1262: 1249: 1241: 1235: 1215:helioseismology 1207: 1164: 1158: 1146: 1140: 1124: 1120: 1111: 1105: 1096: 1090: 1066: 1060: 1048:subdwarf B star 1040: 1034: 1026: 1020: 1007: 1001: 992: 986: 970: 964: 944: 938: 917: 894: 886: 880: 871: 865: 856: 850: 834: 828: 808: 802: 785: 779: 754: 748: 713:Eddington valve 697: 691: 623: 617: 598: 517: 489: 483: 451: 326: 316:. By combining 310: 241:David Fabricius 210: 133: 122: 116: 113: 76:"Variable star" 70: 68: 58: 46: 35: 28: 23: 22: 15: 12: 11: 5: 5790: 5788: 5780: 5779: 5774: 5769: 5767:Variable stars 5759: 5758: 5754: 5753: 5741: 5729: 5717: 5694: 5693: 5691: 5690: 5678: 5667: 5664: 5663: 5661: 5660: 5655: 5650: 5645: 5640: 5635: 5630: 5625: 5624: 5623: 5618: 5617: 5616: 5611: 5595: 5593: 5589: 5588: 5586: 5585: 5580: 5575: 5574: 5573: 5568: 5558: 5553: 5548: 5543: 5538: 5533: 5528: 5527: 5526: 5521: 5520: 5519: 5509: 5504: 5499: 5494: 5489: 5487:Largest volume 5484: 5479: 5474: 5464: 5463: 5462: 5457: 5446: 5444: 5438: 5437: 5435: 5434: 5429: 5424: 5419: 5414: 5413: 5412: 5407: 5402: 5392: 5387: 5382: 5377: 5372: 5371: 5370: 5365: 5360: 5355: 5344: 5342: 5336: 5335: 5333: 5332: 5327: 5326: 5325: 5320: 5315: 5305: 5300: 5299: 5298: 5293: 5288: 5283: 5272: 5270: 5264: 5263: 5261: 5260: 5255: 5250: 5245: 5240: 5235: 5230: 5225: 5220: 5215: 5210: 5205: 5200: 5198:Magnetic field 5195: 5190: 5185: 5180: 5175: 5169: 5167: 5163: 5162: 5160: 5159: 5154: 5149: 5144: 5139: 5134: 5133: 5132: 5122: 5121: 5120: 5115: 5108:Accretion disk 5105: 5104: 5103: 5098: 5088: 5087: 5086: 5084:Alfvén surface 5081: 5079:Stellar corona 5076: 5071: 5066: 5056: 5054:Radiation zone 5051: 5050: 5049: 5044: 5034: 5028: 5026: 5020: 5019: 5017: 5016: 5011: 5010: 5009: 5004: 4999: 4994: 4989: 4979: 4974: 4969: 4964: 4959: 4954: 4949: 4944: 4939: 4934: 4929: 4924: 4919: 4914: 4909: 4903: 4901: 4895: 4894: 4891: 4890: 4888: 4887: 4882: 4877: 4872: 4867: 4862: 4861: 4860: 4855: 4852: 4844: 4843: 4842: 4837: 4832: 4827: 4822: 4817: 4812: 4807: 4802: 4792: 4787: 4781: 4779: 4773: 4772: 4770: 4769: 4764: 4763: 4762: 4752: 4747: 4746: 4745: 4740: 4739: 4738: 4733: 4723: 4713: 4712: 4711: 4701: 4696: 4690: 4688: 4682: 4681: 4679: 4678: 4676:Blue straggler 4673: 4672: 4671: 4661: 4656: 4655: 4654: 4644: 4643: 4642: 4637: 4632: 4627: 4622: 4617: 4612: 4607: 4602: 4592: 4587: 4586: 4585: 4580: 4575: 4565: 4564: 4563: 4553: 4552: 4551: 4546: 4541: 4531: 4526: 4525: 4524: 4519: 4514: 4504: 4499: 4494: 4489: 4488: 4487: 4482: 4472: 4471: 4470: 4465: 4460: 4455: 4450: 4445: 4440: 4434:Main sequence 4432: 4427: 4421: 4415: 4413:Classification 4409: 4408: 4406: 4405: 4404: 4403: 4398: 4388: 4383: 4378: 4373: 4368: 4363: 4358: 4353: 4352: 4351: 4349:Protoplanetary 4341: 4336: 4335: 4334: 4329: 4319: 4318: 4317: 4307: 4302: 4296: 4294: 4288: 4287: 4285: 4284: 4279: 4274: 4269: 4268: 4267: 4262: 4257: 4252: 4242: 4237: 4232: 4226: 4224: 4218: 4217: 4215: 4214: 4208: 4205: 4204: 4199: 4197: 4196: 4189: 4182: 4174: 4165: 4164: 4146: 4143: 4142: 4140: 4139: 4134: 4129: 4124: 4118: 4116: 4110: 4109: 4106: 4105: 4103: 4102: 4097: 4092: 4086: 4084: 4080: 4079: 4077: 4076: 4071: 4065: 4063: 4059: 4058: 4056: 4055: 4049: 4047: 4040: 4036: 4035: 4033: 4032: 4031: 4030: 4023: 4020:Symbiotic nova 4011: 4006: 4005: 4004: 3992: 3991: 3990: 3978: 3973: 3968: 3963: 3957: 3955: 3949: 3948: 3945: 3944: 3942: 3941: 3936: 3934:Lambda Eridani 3931: 3926: 3920: 3918: 3914: 3913: 3911: 3910: 3905: 3900: 3894: 3892: 3888: 3887: 3885: 3884: 3879: 3867: 3861: 3859: 3853: 3852: 3850: 3849: 3848: 3847: 3840: 3828: 3822: 3820: 3807: 3803: 3802: 3799: 3798: 3796: 3795: 3790: 3785: 3779: 3777: 3773: 3772: 3770: 3769: 3767:Slow irregular 3764: 3759: 3753: 3751: 3745: 3744: 3742: 3741: 3736: 3731: 3726: 3721: 3715: 3713: 3707: 3706: 3704: 3703: 3698: 3693: 3688: 3668: 3651: 3649: 3637: 3631: 3630: 3627:Variable stars 3625: 3623: 3622: 3615: 3608: 3600: 3594: 3593: 3588: 3583: 3576: 3575:External links 3573: 3572: 3571: 3535: 3532: 3529: 3528: 3523:10.1086/166419 3493: 3464:(1): 229–235. 3444: 3422: 3398: 3339: 3286: 3280:10.1086/513870 3265:(1): 219–248. 3245: 3238: 3212: 3165: 3124: 3097: 3062: 3056:, John Percy, 3039: 3026:10.1086/345715 2986: 2973:10.1086/513012 2933: 2914:(7): 556–561. 2898: 2887:10.1086/147661 2853: 2816: 2763: 2756: 2736: 2712: 2688: 2661: 2638: 2614: 2597: 2590: 2572: 2523: 2456: 2387: 2334: 2307:(3): 327–339. 2287: 2260:(1–4): 53–65. 2244: 2232: 2201: 2200: 2198: 2195: 2194: 2193: 2188: 2183: 2178: 2171: 2168: 2164:Kepler Mission 2146: 2143: 2135:Main article: 2132: 2129: 2123: 2120: 2108:Main article: 2105: 2102: 2090:Main article: 2087: 2084: 2067:Algol variable 2065:Main article: 2062: 2059: 2026:Main article: 2023: 2020: 1996:Main article: 1993: 1990: 1982:Main article: 1979: 1976: 1964:Main article: 1961: 1958: 1956: 1953: 1945:Main article: 1942: 1939: 1919:emission lines 1912:spectral types 1882: 1879: 1873:). The star's 1866: 1863: 1857: 1854: 1852: 1849: 1847:the observer. 1839: 1836: 1831: 1828: 1819:Main article: 1816: 1813: 1800:Main article: 1797: 1794: 1785:Main article: 1782: 1779: 1770:Main article: 1767: 1764: 1763: 1762: 1758:superoutbursts 1750: 1740: 1714:Main article: 1711: 1708: 1684:binary systems 1668:Main article: 1665: 1662: 1650:Main article: 1636: 1633: 1571:Main article: 1568: 1565: 1553: 1550: 1541:Main article: 1538: 1535: 1510:Main article: 1507: 1504: 1489:Main article: 1486: 1483: 1458:Main article: 1455: 1452: 1435:Main article: 1432: 1429: 1416:Main article: 1413: 1410: 1383:Main article: 1380: 1377: 1372: 1369: 1348:Main article: 1345: 1342: 1324:Orion variable 1322:Main article: 1319: 1316: 1300:Main article: 1284: 1281: 1273:Main article: 1270: 1267: 1261: 1258: 1256:observations. 1248: 1245: 1237:Main article: 1234: 1233:BLAP variables 1231: 1206: 1203: 1160:Main article: 1157: 1154: 1142:Main article: 1139: 1136: 1122: 1118: 1107:Main article: 1104: 1101: 1092:Main article: 1089: 1086: 1062:Main article: 1059: 1056: 1036:Main article: 1033: 1030: 1022:Main article: 1019: 1016: 1003:Main article: 1000: 997: 988:Main article: 985: 982: 966:Main article: 963: 960: 940:Main article: 937: 934: 913:Main article: 893: 892:Mira variables 890: 882:Main article: 879: 876: 867:Main article: 864: 861: 852:Main article: 849: 846: 838:Dwarf Cepheids 830:Main article: 827: 824: 804:Main article: 801: 798: 781:Main article: 778: 775: 771:John Goodricke 750:Main article: 747: 744: 693:Main article: 690: 687: 619:Main article: 616: 613: 597: 594: 582: 581: 580: 579: 575: 554: 553: 552: 541: 538: 516: 515:Classification 513: 485:Main article: 482: 479: 450: 447: 443: 442: 439: 436: 433:Doppler effect 429: 426: 423: 420: 397: 396: 393: 390: 325: 322: 309: 306: 260:John Goodricke 209: 206: 190: 189: 179: 143:Comparison of 135: 134: 49: 47: 40: 26: 24: 18:Variable stars 14: 13: 10: 9: 6: 4: 3: 2: 5789: 5778: 5775: 5773: 5770: 5768: 5765: 5764: 5762: 5752: 5742: 5740: 5730: 5728: 5718: 5716: 5706: 5702: 5689: 5684: 5679: 5677: 5669: 5668: 5665: 5659: 5656: 5654: 5651: 5649: 5648:Intergalactic 5646: 5644: 5641: 5639: 5636: 5634: 5631: 5629: 5628:Galactic year 5626: 5622: 5619: 5615: 5612: 5610: 5607: 5606: 5605: 5602: 5601: 5600: 5597: 5596: 5594: 5590: 5584: 5581: 5579: 5576: 5572: 5569: 5567: 5564: 5563: 5562: 5559: 5557: 5554: 5552: 5549: 5547: 5544: 5542: 5539: 5537: 5534: 5532: 5529: 5525: 5522: 5518: 5515: 5514: 5513: 5510: 5508: 5507:Most luminous 5505: 5503: 5500: 5498: 5495: 5493: 5490: 5488: 5485: 5483: 5480: 5478: 5475: 5473: 5470: 5469: 5468: 5465: 5461: 5458: 5456: 5453: 5452: 5451: 5448: 5447: 5445: 5443: 5439: 5433: 5430: 5428: 5425: 5423: 5422:Proper motion 5420: 5418: 5415: 5411: 5408: 5406: 5403: 5401: 5398: 5397: 5396: 5393: 5391: 5388: 5386: 5385:Constellation 5383: 5381: 5378: 5376: 5373: 5369: 5366: 5364: 5361: 5359: 5356: 5354: 5353:Solar eclipse 5351: 5350: 5349: 5346: 5345: 5343: 5339:Earth-centric 5337: 5331: 5328: 5324: 5321: 5319: 5316: 5314: 5311: 5310: 5309: 5306: 5304: 5301: 5297: 5294: 5292: 5289: 5287: 5284: 5282: 5279: 5278: 5277: 5274: 5273: 5271: 5269: 5265: 5259: 5256: 5254: 5251: 5249: 5246: 5244: 5241: 5239: 5236: 5234: 5231: 5229: 5226: 5224: 5221: 5219: 5216: 5214: 5211: 5209: 5206: 5204: 5201: 5199: 5196: 5194: 5191: 5189: 5186: 5184: 5181: 5179: 5176: 5174: 5171: 5170: 5168: 5164: 5158: 5155: 5153: 5150: 5148: 5145: 5143: 5140: 5138: 5135: 5131: 5128: 5127: 5126: 5123: 5119: 5116: 5114: 5111: 5110: 5109: 5106: 5102: 5099: 5097: 5094: 5093: 5092: 5089: 5085: 5082: 5080: 5077: 5075: 5072: 5070: 5067: 5065: 5062: 5061: 5060: 5057: 5055: 5052: 5048: 5045: 5043: 5040: 5039: 5038: 5035: 5033: 5030: 5029: 5027: 5025: 5021: 5015: 5012: 5008: 5005: 5003: 5000: 4998: 4995: 4993: 4990: 4988: 4985: 4984: 4983: 4980: 4978: 4975: 4973: 4970: 4968: 4965: 4963: 4960: 4958: 4955: 4953: 4950: 4948: 4945: 4943: 4940: 4938: 4937:Alpha process 4935: 4933: 4930: 4928: 4925: 4923: 4920: 4918: 4915: 4913: 4910: 4908: 4905: 4904: 4902: 4900: 4896: 4886: 4883: 4881: 4878: 4876: 4873: 4871: 4868: 4866: 4863: 4859: 4856: 4853: 4851: 4848: 4847: 4845: 4841: 4838: 4836: 4833: 4831: 4828: 4826: 4823: 4821: 4818: 4816: 4813: 4811: 4808: 4806: 4803: 4801: 4798: 4797: 4796: 4793: 4791: 4788: 4786: 4783: 4782: 4780: 4778: 4774: 4768: 4765: 4761: 4758: 4757: 4756: 4753: 4751: 4748: 4744: 4741: 4737: 4734: 4732: 4729: 4728: 4727: 4724: 4722: 4719: 4718: 4717: 4714: 4710: 4709:Helium planet 4707: 4706: 4705: 4702: 4700: 4699:Parker's star 4697: 4695: 4692: 4691: 4689: 4687: 4683: 4677: 4674: 4670: 4667: 4666: 4665: 4662: 4660: 4657: 4653: 4650: 4649: 4648: 4645: 4641: 4638: 4636: 4633: 4631: 4630:Lambda Boötis 4628: 4626: 4623: 4621: 4618: 4616: 4613: 4611: 4608: 4606: 4603: 4601: 4598: 4597: 4596: 4593: 4591: 4588: 4584: 4581: 4579: 4576: 4574: 4571: 4570: 4569: 4566: 4562: 4559: 4558: 4557: 4554: 4550: 4547: 4545: 4542: 4540: 4537: 4536: 4535: 4532: 4530: 4527: 4523: 4520: 4518: 4515: 4513: 4510: 4509: 4508: 4505: 4503: 4500: 4498: 4495: 4493: 4490: 4486: 4483: 4481: 4478: 4477: 4476: 4473: 4469: 4466: 4464: 4461: 4459: 4456: 4454: 4451: 4449: 4446: 4444: 4441: 4439: 4436: 4435: 4433: 4431: 4428: 4426: 4423: 4422: 4419: 4416: 4414: 4410: 4402: 4399: 4397: 4396:Superluminous 4394: 4393: 4392: 4389: 4387: 4384: 4382: 4379: 4377: 4374: 4372: 4369: 4367: 4364: 4362: 4359: 4357: 4354: 4350: 4347: 4346: 4345: 4342: 4340: 4337: 4333: 4330: 4328: 4325: 4324: 4323: 4320: 4316: 4313: 4312: 4311: 4308: 4306: 4303: 4301: 4300:Main sequence 4298: 4297: 4295: 4293: 4289: 4283: 4280: 4278: 4277:Hayashi track 4275: 4273: 4270: 4266: 4263: 4261: 4258: 4256: 4253: 4251: 4248: 4247: 4246: 4243: 4241: 4238: 4236: 4233: 4231: 4228: 4227: 4225: 4223: 4219: 4213: 4210: 4209: 4206: 4202: 4195: 4190: 4188: 4183: 4181: 4176: 4175: 4172: 4162: 4158: 4157: 4152: 4144: 4138: 4135: 4133: 4130: 4128: 4125: 4123: 4120: 4119: 4117: 4115: 4111: 4101: 4098: 4096: 4093: 4091: 4088: 4087: 4085: 4081: 4075: 4072: 4070: 4067: 4066: 4064: 4062:Stellar spots 4060: 4054: 4051: 4050: 4048: 4046:Non-spherical 4044: 4041: 4037: 4028: 4024: 4021: 4017: 4016: 4015: 4012: 4010: 4007: 4002: 3998: 3997: 3996: 3993: 3988: 3984: 3983: 3982: 3979: 3977: 3974: 3972: 3969: 3967: 3964: 3962: 3959: 3958: 3956: 3954: 3950: 3940: 3937: 3935: 3932: 3930: 3927: 3925: 3922: 3921: 3919: 3915: 3909: 3906: 3904: 3901: 3899: 3896: 3895: 3893: 3889: 3883: 3880: 3876: 3871: 3868: 3866: 3863: 3862: 3860: 3854: 3845: 3841: 3838: 3834: 3833: 3832: 3829: 3827: 3824: 3823: 3821: 3819: 3815: 3811: 3808: 3804: 3794: 3791: 3789: 3786: 3784: 3783:Gamma Doradus 3781: 3780: 3778: 3774: 3768: 3765: 3763: 3760: 3758: 3755: 3754: 3752: 3750: 3746: 3740: 3737: 3735: 3734:PV Telescopii 3732: 3730: 3727: 3725: 3722: 3720: 3717: 3716: 3714: 3712:early spectra 3708: 3702: 3699: 3697: 3694: 3692: 3689: 3685: 3681: 3677: 3672: 3669: 3665: 3661: 3656: 3653: 3652: 3650: 3645: 3641: 3638: 3636: 3632: 3628: 3621: 3616: 3614: 3609: 3607: 3602: 3601: 3598: 3592: 3589: 3587: 3584: 3582: 3579: 3578: 3574: 3560: 3555: 3551: 3547: 3543: 3538: 3537: 3533: 3524: 3520: 3516: 3512: 3508: 3504: 3497: 3494: 3489: 3485: 3480: 3475: 3471: 3467: 3463: 3459: 3455: 3448: 3445: 3432: 3426: 3423: 3412: 3411:www.aavso.org 3408: 3402: 3399: 3394: 3390: 3385: 3380: 3376: 3372: 3367: 3362: 3358: 3354: 3350: 3343: 3340: 3335: 3331: 3327: 3323: 3319: 3315: 3310: 3305: 3301: 3297: 3290: 3287: 3281: 3276: 3272: 3268: 3264: 3260: 3256: 3249: 3246: 3241: 3239:0-333-75088-8 3235: 3231: 3227: 3223: 3216: 3213: 3208: 3204: 3200: 3196: 3192: 3188: 3184: 3180: 3176: 3169: 3166: 3160: 3155: 3151: 3147: 3143: 3139: 3135: 3128: 3125: 3120: 3116: 3112: 3108: 3101: 3098: 3093: 3089: 3085: 3081: 3077: 3073: 3066: 3063: 3059: 3055: 3051: 3048: 3043: 3040: 3035: 3031: 3027: 3023: 3018: 3013: 3009: 3005: 3001: 2997: 2990: 2987: 2982: 2978: 2974: 2970: 2966: 2962: 2957: 2952: 2948: 2944: 2937: 2934: 2929: 2925: 2921: 2917: 2913: 2909: 2908:New Astronomy 2902: 2899: 2888: 2884: 2880: 2876: 2872: 2868: 2864: 2857: 2854: 2843: 2839: 2835: 2831: 2827: 2820: 2817: 2806: 2802: 2798: 2794: 2790: 2786: 2782: 2778: 2774: 2767: 2764: 2759: 2753: 2749: 2748: 2740: 2737: 2726: 2722: 2716: 2713: 2698: 2692: 2689: 2684: 2680: 2676: 2672: 2665: 2662: 2657: 2653: 2649: 2642: 2639: 2628: 2624: 2618: 2615: 2610: 2609: 2601: 2598: 2593: 2591:9781760877200 2587: 2583: 2576: 2573: 2568: 2564: 2560: 2556: 2551: 2546: 2542: 2538: 2534: 2527: 2524: 2519: 2515: 2510: 2505: 2501: 2497: 2493: 2489: 2484: 2479: 2476:(1): 89–107. 2475: 2471: 2467: 2460: 2457: 2452: 2448: 2443: 2438: 2433: 2428: 2424: 2420: 2415: 2410: 2406: 2402: 2398: 2391: 2388: 2383: 2379: 2375: 2371: 2367: 2363: 2358: 2353: 2349: 2345: 2338: 2335: 2330: 2326: 2322: 2318: 2314: 2310: 2306: 2302: 2298: 2291: 2288: 2283: 2279: 2275: 2271: 2267: 2263: 2259: 2255: 2248: 2245: 2235: 2229: 2225: 2221: 2217: 2213: 2206: 2203: 2196: 2192: 2189: 2187: 2184: 2182: 2179: 2177: 2174: 2173: 2169: 2167: 2165: 2161: 2157: 2152: 2144: 2142: 2138: 2130: 2128: 2121: 2119: 2117: 2111: 2103: 2101: 2099: 2093: 2085: 2083: 2081: 2078: 2077:constellation 2074: 2068: 2060: 2058: 2056: 2052: 2048: 2039: 2034: 2029: 2021: 2019: 2017: 2013: 2012:neutron stars 2009: 2008:visible light 2005: 1999: 1991: 1989: 1985: 1977: 1975: 1973: 1972:main-sequence 1967: 1959: 1954: 1952: 1948: 1940: 1938: 1936: 1932: 1928: 1924: 1920: 1917: 1916:chromospheric 1913: 1909: 1905: 1897: 1896: 1891: 1887: 1880: 1878: 1876: 1872: 1865:Stellar spots 1864: 1862: 1855: 1850: 1848: 1845: 1837: 1835: 1829: 1827: 1822: 1814: 1812: 1810: 1803: 1795: 1793: 1788: 1780: 1778: 1773: 1765: 1760: 1759: 1754: 1751: 1748: 1744: 1741: 1738: 1734: 1730: 1727: 1726: 1725: 1723: 1717: 1709: 1707: 1705: 1701: 1697: 1693: 1689: 1685: 1681: 1676: 1671: 1663: 1661: 1659: 1653: 1646: 1641: 1634: 1632: 1629: 1624: 1622: 1618: 1612: 1610: 1606: 1603:(generally a 1602: 1598: 1594: 1590: 1589: 1584: 1580: 1574: 1566: 1563: 1559: 1551: 1549: 1544: 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These 1844:sunspots 1617:SN 1987A 1531:Wolf 359 1471:nitrogen 1184:V777 Her 1070:hydrogen 671:pressure 667:acoustic 646:overtone 642:harmonic 509:RR Lyrae 471:cepheids 419:, etc.)? 314:spectrum 272:R Hydrae 268:G. Kirch 5701:Portals 5643:Gravity 5592:Related 5512:Nearest 5460:Chinese 5308:Cluster 5281:Contact 5118:Proplyd 4992:Remnant 4880:Blitzar 4854:Hawking 4810:Strange 4760:Burster 4716:Neutron 4669:Extreme 4620:He-weak 4265:T Tauri 3844:T Tauri 3671:Type II 3511:Bibcode 3509:: 764. 3466:Bibcode 3371:Bibcode 3334:9481357 3314:Bibcode 3267:Bibcode 3226:Bibcode 3187:Bibcode 3146:Bibcode 3115:Bibcode 3113:: 196. 3080:Bibcode 3004:Bibcode 2981:2445038 2961:Bibcode 2916:Bibcode 2875:Bibcode 2873:: 487. 2838:Bibcode 2785:Bibcode 2679:Bibcode 2677:: 266. 2488:Bibcode 2442:4683080 2419:Bibcode 2362:Bibcode 2309:Bibcode 2262:Bibcode 2151:planets 2116:Sheliak 2080:Perseus 2075:in the 2051:eclipse 2004:pulsars 1904:equator 1619:in the 1607:) or a 1522:UV Ceti 1402:P Cygni 1367:stars. 1364:T Tauri 1334:T Tauri 1201:stars. 1174:ZZ Ceti 908:χ Cygni 679:gravity 270:, then 226:Antares 101:scholar 5633:Galaxy 5621:Planet 5609:Desert 5517:bright 5455:Arabic 5276:Binary 5096:Bubble 4820:Planck 4795:Exotic 4731:Binary 4726:Pulsar 4664:Helium 4625:Barium 4568:Carbon 4561:Yellow 4549:Yellow 4522:Yellow 4361:PG1159 4095:Pulsar 3655:Type I 3486: 3391: 3332: 3236: 3205: 3032: 3014: 2979: 2803: 2754: 2588: 2565: 2516: 2449: 2439: 2380: 2327: 2280: 2230: 1998:Pulsar 1923:FK Com 1737:Cygnus 1605:pulsar 1579:galaxy 1479:oxygen 1475:carbon 1467:helium 1310:mass) 1190:GW Vir 1132:Cygnus 1078:helium 1074:carbon 1052:p-mode 683:g-mode 675:p-mode 627:radial 578:shape. 475:helium 361:period 103: 96: 89: 82: 74: 5638:Guest 5442:Lists 5323:Super 4977:Fusor 4850:Black 4835:Quark 4815:Preon 4800:Boson 4736:X-ray 4652:Shell 4605:Ap/Bp 4507:Giant 4425:Early 4371:OH/IR 4201:Stars 4122:Algol 3981:Polar 3924:Flare 3917:Other 3831:Orion 3776:Other 3484:S2CID 3389:S2CID 3361:arXiv 3330:S2CID 3304:arXiv 3203:S2CID 3058:AAVSO 3030:S2CID 2977:S2CID 2951:arXiv 2836:: 3. 2801:S2CID 2700:(PDF) 2563:S2CID 2545:arXiv 2514:S2CID 2478:arXiv 2409:arXiv 2378:S2CID 2352:arXiv 2325:S2CID 2278:S2CID 2073:Algol 2055:Algol 1675:Novae 1664:Novae 1658:novae 1597:China 1308:solar 1181:, or 1171:, or 1128:Deneb 572:Earth 545:novae 505:Bayer 214:Algol 167:(its 165:Earth 159:is a 108:JSTOR 94:books 5313:Open 5208:Mass 5032:Core 4982:Nova 4875:Iron 4825:Dark 4635:Lead 4615:HgMn 4610:CEMP 4539:Blue 4512:Blue 4430:Late 4212:List 4161:List 3976:Nova 3816:and 3757:Mira 3567:2023 3439:2021 3234:ISBN 2752:ISBN 2707:2020 2586:ISBN 2447:PMID 2228:ISBN 2158:and 2036:How 2002:Few 1929:and 1895:TESS 1692:slow 1688:fast 1670:Nova 1560:and 1529:and 1477:and 1400:and 1254:TESS 1209:The 1199:PNNV 1197:and 1121:to A 1076:and 929:Mira 547:and 351:and 282:and 224:and 161:star 80:news 5614:Sub 5348:Sun 4767:SGR 4544:Red 4517:Red 3818:PMS 3646:and 3554:doi 3519:doi 3507:329 3474:doi 3462:467 3379:doi 3357:902 3322:doi 3300:426 3275:doi 3263:171 3195:doi 3154:doi 3142:150 3111:259 3088:doi 3022:doi 3000:584 2969:doi 2947:660 2924:doi 2883:doi 2871:138 2793:doi 2555:doi 2504:hdl 2496:doi 2437:PMC 2427:doi 2370:doi 2348:773 2317:doi 2270:doi 2258:125 2220:doi 1694:or 1211:Sun 1195:DOV 1179:DBV 1169:DAV 976:or 950:or 903:of 669:or 644:or 566:or 523:or 198:Sun 63:by 5763:: 4647:Be 4600:Am 4583:CH 4578:CN 4497:OB 4492:WR 4159:* 3682:, 3678:, 3662:, 3550:90 3548:. 3544:. 3517:. 3505:. 3482:. 3472:. 3460:. 3456:. 3409:. 3387:. 3377:. 3369:. 3355:. 3351:. 3328:. 3320:. 3312:. 3298:. 3273:. 3261:. 3257:. 3232:. 3224:. 3201:. 3193:. 3183:53 3181:. 3177:. 3152:. 3140:. 3136:. 3109:. 3086:. 3076:16 3074:. 3028:. 3020:. 3010:. 2998:. 2975:. 2967:. 2959:. 2945:. 2922:. 2912:12 2910:. 2881:. 2869:. 2865:. 2834:28 2832:. 2828:. 2799:. 2791:. 2779:. 2775:. 2723:. 2675:14 2673:. 2650:. 2625:. 2561:. 2553:. 2541:21 2539:. 2535:. 2512:. 2502:. 2494:. 2486:. 2474:29 2472:. 2468:. 2445:. 2435:. 2425:. 2417:. 2405:10 2403:. 2399:. 2376:. 2368:. 2360:. 2346:. 2323:. 2315:. 2305:18 2303:. 2299:. 2276:. 2268:. 2256:. 2226:, 2214:, 2166:. 2100:. 2082:. 2018:. 1937:. 1925:, 1811:. 1690:, 1623:. 1611:. 1533:. 1473:, 1469:, 1427:. 1229:. 1123:ep 1119:ep 1084:. 742:. 661:. 592:. 527:. 415:, 411:, 347:, 216:. 204:. 155:A 5703:: 4840:Q 4659:B 4573:S 4485:B 4480:O 4468:M 4463:K 4458:G 4453:F 4448:A 4443:B 4438:O 4193:e 4186:t 4179:v 3877:) 3873:( 3686:) 3674:( 3666:) 3658:( 3619:e 3612:t 3605:v 3569:. 3556:: 3525:. 3521:: 3513:: 3490:. 3476:: 3468:: 3441:. 3419:. 3395:. 3381:: 3373:: 3363:: 3336:. 3324:: 3316:: 3306:: 3283:. 3277:: 3269:: 3242:. 3228:: 3209:. 3197:: 3189:: 3162:. 3156:: 3148:: 3121:. 3117:: 3094:. 3090:: 3082:: 3036:. 3024:: 3006:: 2983:. 2971:: 2963:: 2953:: 2930:. 2926:: 2918:: 2895:. 2885:: 2877:: 2850:. 2840:: 2813:. 2795:: 2787:: 2781:7 2760:. 2733:. 2709:. 2685:. 2681:: 2635:. 2594:. 2569:. 2557:: 2547:: 2520:. 2506:: 2498:: 2490:: 2480:: 2453:. 2429:: 2421:: 2411:: 2384:. 2372:: 2364:: 2354:: 2331:. 2319:: 2311:: 2284:. 2272:: 2264:: 2222:: 1678:( 1117:B 551:. 435:) 407:( 188:. 130:) 124:( 119:) 115:( 105:· 98:· 91:· 84:· 57:. 34:. 20:)

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