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Gamma Eridani
Gamma Eridani (γ Eridani, abbreviated Gamma Eri, γ Eri), formally named Zaurak , is a variable star in the constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude that varies around 2.9, and lies at a distance of about 203 light years from the Sun, as determined by the Hipparcos astrometry satellite. Description Gamma Eridani has been defined as a standard star for the spectral class M0III-IIIb. It is a red giant on the asymptotic giant branch, fusing hydrogen and helium in separate shells outside its core. Observations published in 1960 showed it to vary in brightness by a few hundredths of a magnitude. In 1977, it was officially listed as a variable star in the General Catalogue of Variable Stars although the class of variable is uncertain. Nomenclature ''Gamma Eridani'' is the star's Bayer designation. It has the traditional name ''Zaurak'', alternatively spelled Zaurac, which is Arabic for 'boat'. In 2016, the In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eridanus (constellation)
Eridanus () is a constellation in the southern celestial hemisphere. It is represented as a river. One of the 48 constellations listed by the 2nd century astronomer Ptolemy, it remains one of the 88 modern constellations. It is the sixth largest of the modern constellations, and the one that extends farthest in the sky from north to south. The same name was later taken as a Latin name for the real Po River and also for the name of a minor river in Athens. Features Stars At its southern end is the magnitude 0.5 star Achernar, designated Alpha Eridani. It is a blue-white hued main sequence star 144 light-years from Earth, whose traditional name means "the river's end". Achernar is a very peculiar star because it is one of the flattest stars known. Observations indicate that its radius is about 50% larger at the equator than at the poles. This distortion occurs because the star is spinning extremely rapidly. There are several other noteworthy stars in Eridanus, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Catalogue Of Variable Stars
The General Catalogue of Variable Stars (GCVS) is a list of variable stars. Its first edition, containing 10,820 stars, was published in 1948 by the Academy of Sciences of the USSR and edited by B. V. Kukarkin and P. P. Parenago. Second and third editions were published in 1958 and 1968; the fourth edition, in three volumes, was published 1985–1987. It contained 28,435 stars. A fourth volume of the fourth edition containing reference tables was later published, as well as a fifth volume containing variable stars outside the Galaxy. The last edition (GCVS v5.1) based on data compiled in 2015 gathers 52,011 variable stars. The most up-to-date version of the GCVS is available at the GCVS website. It contains improved coordinates for the variable stars in the printed fourth edition of the GCVS, as well as variable stars discovered too recently to be included in the fourth edition. An older version of the GCVS dating from 2004 is available from the VizieR service at the Ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tau3 Eridani
Tau3 Eridani, Latinized from τ3 Eridani, is a star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 4.10. Using the parallax method, the distance to this star can be estimated as 88.6 light years. In 2001 it was reported as a candidate Vega-like star, meaning it appears to radiate an infrared excess from an orbiting circumstellar disk. However, this has not been confirmed. This is an A-type star with a stellar classification of A3 IV-V. The luminosity class of IV-V indicates the spectrum displays traits intermediate between a main sequence and subgiant star. It is around 476 million years old and is spinning rapidly with a projected rotational velocity of 133 km/s. This is creating an equatorial bulge that might be 7% wider than the polar radius. Tau3 Eridani has 178% of the Sun's mass and nearly double the radius of the Sun. The star shines with 13.7 times the solar luminosity The solar luminosity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tau2 Eridani
Tau2 Eridani (τ2 Eridani, abbreviated Tau2 Eri, τ2 Eri), formally named Angetenar , is a star in the constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude of 4.78. The distance to this star, as determined via the parallax method, is around 187 light-years. Nomenclature ''τ2 Eridani'' ( Latinised to ''Tau2 Eridani'') is the system's Bayer designation. It is one of a series of stars that share the Bayer designation Tau Eridani. It bore the traditional name ''Angetenar'', derived from the Arabic ''Al Ḥināyat an-Nahr'', 'the Bend in the River', near which it lies. In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ''Angetenar'' for this star on 30 June 2017 and it is now so included in the List of IAU-approved Star Names. In Chinese, (), meaning '' Celestial Meadows'', refers to an asterism consisting of Tau2 Eridani, Gamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tau1 Eridani
Tau1 Eridani, Latinized from τ1 Eridani, is a binary star system in the constellation Eridanus. It has an apparent magnitude of 4.46, making it visible to the naked eye in suitably dark conditions. This a spectroscopic binary with an orbital period of 958 days. It is located about 46 light years from the Earth. At present, the system is moving away from the Sun with a radial velocity of +26 km/s. About 305,000 years ago, it made perihelion passage at an estimated distance of . Tau1 Eridani was a latter designation of 90 Ceti. Debris disk A moderate far-infrared excess was observed for this star system, in the 12μm, 25μm, 60μm and 100μm wavelengths, by the Infrared Astronomical Satellite The Infrared Astronomical Satellite (Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten mon ... (IRAS), an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pi Ceti
Pi Ceti, Latinized from π Ceti, is the Bayer designation for a star system in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 4.238. Observed to have an Earth half yearly parallax shift of 8.30 mas, it is around 393 light years from the Sun. This is a single-lined spectroscopic binary system with a nearly circular orbit and a period of 7.45 years. The fact that the system has a negligible eccentricity is surprising for such a long period, and may suggest that the secondary is a white dwarf that had its orbit circularized during a mass-transfer event. The primary, component A, is a normal B-type star that has been given stellar classifications of B7 V and B7 IV. It appears very young – less than half a million years in age – and may still be on a pre-main sequence track. The star shows no magnetic field but it does emit an infrared excess. Name This star, along with ε Cet, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Eridani
Eta Eridani (η Eridani, abbreviated Eta Eri, η Eri), officially named Azha (with a silent 'h', possibly ), is a giant star in the constellation of Eridanus. Based on parallax measurements taken during the Hipparcos mission, it is approximately 137 light-years from the Sun. Nomenclature ''η Eridani'' ( Latinised to ''Eta Eridani'') is the star's Bayer designation. It bore the traditional name ''Azha'', from the old Arab asterism نَعَام أُدْحِيّ ''udḥiyy al-naʽām'' "the ostrich nest" (or "hatching place"), which included Eta Eridani. The first word, ادحى ''udḥiyy'', was miscopied as ازحى (readable as ''azḥā'') in medieval manuscripts. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name ''Azha'' for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names. In Chinese, (), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta Eridani
Zeta Eridani (ζ Eridani, abbreviated Zeta Eri, ζ Eri) is a binary star in the constellation of Eridanus. With an apparent visual magnitude of 4.80, it is visible to the naked eye on a clear dark night. Based on parallax measurements taken during the Hipparcos mission, it is approximately 110 light-years from the Sun. Zeta Eridani is the primary or 'A' component of a multiple star system designated WDS J03158-0849 (the secondary or 'B' component is 14 Eridani). Zeta Eridani's two components are therefore designated WDS J03158-0849 Aa and Ab. Aa is formally named Zibal , the traditional name for the system. Nomenclature ''ζ Eridani'' ( Latinised to ''Zeta Eridani'') is the binary star's Bayer designation. WDS J03158-0849 A is its designation in the Washington Double Star Catalog. The designations of the two components as WDS J03158-0849 Aa and Ab derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and ado ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Eridani
Epsilon Eridani ( Latinized from ε Eridani), formally named Ran, is a star in the southern constellation of Eridanus, at a declination of 9.46° south of the celestial equator. This allows it to be visible from most of Earth's surface. At a distance of from the Sun, it has an apparent magnitude of 3.73. It is the third-closest individual star or star system visible to the unaided eye. The star is estimated to be less than a billion years old. Because of its relative youth, Epsilon Eridani has a higher level of magnetic activity than the present-day Sun, with a stellar wind 30 times as strong. Its rotation period is 11.2 days at the equator. Epsilon Eridani is smaller and less massive than the Sun, and has a comparatively lower level of elements heavier than helium. It is a main-sequence star of spectral class K2, which means that energy generated at the core through nuclear fusion of hydrogen is emitted from the surface at a temperature of about , giving it an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pi Eridani
Pi Eridani, Latinized from π Eridani, is a star in the constellation Eridanus. It has an apparent visual magnitude of 4.40, which is bright enough to be seen on a dark, clear night. Based upon parallax measurements, it is located roughly 480 light years from the Sun. This is an evolved red giant star with a stellar classification of M1 III, and is currently on the asymptotic giant branch. It is a slow irregular variable type LB that can increase in magnitude up to 4.38. The measured angular diameter of this star is . At the estimated distance of Pi Eridani, this yields a physical size of about 77 times the radius of the Sun. It shines with 1,123 times the luminosity of the Sun from an outer atmosphere at an effective temperature of 3,841 K. References {{DEFAULTSORT:Pi Eridani M-type giants Asymptotic-giant-branch stars Slow irregular variables Eridanus (constellation) Eridani, Pi Durchmusterung objects Eridani, 26 023614 017593 1162 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Eridani
Delta Eridani, which is Latinized from δ Eridani, is a star in the equatorial constellation of Eridanus. The star is visible to the naked eye and has been observed to vary in slightly brightness between magnitudes 3.51 and 3.56, although subsequent observations did not bear this out. It is relatively near to the Sun, with a distance of about 29.5 light years as determined from parallax. The star is drifting closer with a radial velocity of −6 km/s. Delta Eridani is sometimes called Rana: ''Rana'' means "the frog" in Latin, but derivation of this name is uncertain. The name was approved by the International Astronomic Union on 4 April 2022. Structure The stellar classification of this star is K0 IV, matching a subgiant star that has exhausted its core hydrogen. This has caused the star to expand and become cooler than a comparable main sequence star. Stellar modelling indicates it is near the end of the subgiant stage and about to transition in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hairy Head (Chinese Constellation)
The Hairy Head mansion (昴宿, pinyin: Mǎo Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the western mansions of the White Tiger. This mansion corresponds to the Pleiades The Pleiades (), also known as The Seven Sisters, Messier 45 and other names by different cultures, is an asterism and an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. At a distance ... in English. Asterisms {{DEFAULTSORT:Hairy Head (Chinese Constellation) Chinese constellations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
