Gamma Tauri

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Template:Short description

γ Tauri
Template:Location mark
Location of γ Tauri (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) 3.654[2]
Characteristics
Evolutionary stage red clump[3]
Spectral type G8III[4]
U−B Template:Engvar +0.84[5]
B−V Template:Engvar +0.99[5]
Astrometry
Radial velocity (Rv)38.7 ± 0.9[6] km/s
Proper motion (μ) RA: +115.29[1] mas/yr
Dec.: -23.86[1] mas/yr
Parallax (π)21.17±1.17 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)0.22[4]
Details
Mass2.70 ± 0.13[7] Template:Solar mass
Radius13.4 ± 0.2[8] Template:Solar radius
Luminosity85[4] Template:Solar luminosity
Surface gravity (log g)2.58-2.61[8] cgs
Temperature4,844 ± 47[8] K
Metallicity [Fe/H]+0.11[9] dex
Rotation253 days[10]
Rotational velocity (v sin i)4[11] km/s
Age430–530[4][7] Myr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Prima Hyadum, Hyadum I,[12] 54 Tauri, BD+15°612, FK5 159, HD 27371, HIP 20205, HR 1346, SAO 93868, GC 5226, WDS 04198+1538[2]
Database references
SIMBADdata

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Gamma Tauri (γ Tauri, abbreviated Gamma Tau, γ Tau) is either a solitary, binary or double star (the Washington Double Star Catalog notes it as a "Dubious Double" or "Bogus Binary"[13]) that marks the tip of the "V" in the constellation of Taurus. It is a member of, and located within about 2.5 parsecs of the center of, the Hyades star cluster, the nearest open cluster to the Sun. Based upon parallax measurements, Gamma Tauri is approximately 154 light-years from the Sun.

Considered as a pair of stars, the two components are designated Gamma Tauri A (officially named Prima Hyadum Template:IPAc-en, the traditional name for the system)[14] and B.

Nomenclature

γ Tauri (Latinised to Gamma Tauri) is the system's Bayer designation. The designations of the two potential components as Gamma Tauri A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[15]

Gamma Tauri bore the traditional name Hyadum I,[12] which is Latin for "First of the Hyades". In 2016, the IAU organized a Working Group on Star Names (WGSN)[16] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[17] It approved the name Prima Hyadum for the component Gamma Tauri A on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[14]

In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Net, refers to an asterism consisting of Gamma Tauri, Epsilon Tauri, Delta³ Tauri, Delta¹ Tauri, Alpha Tauri (Aldebaran), 71 Tauri and Lambda Tauri.[18] Consequently, the Chinese name for γ Tauri itself is Script error: No such module "Lang". (Script error: No such module "Lang".), "the Fourth Star of Net".[19]

Properties

Gamma Tauri presents as a spectral class G8 or K0[2][4] giant star with an apparent magnitude of +3.65. This star has passed through the main sequence phase is now a red clump giant, meaning it is using nuclear fusion of helium at its core to provide energy.[3] Age estimates for Gamma Tauri range from 430 million[4] to 530 million years.[7] By comparison, the age of the Hyades cluster is about 625 million years with an error margin of 50 million years.[7]

The angular diameter of this star has been measured using the CHARA array to 2% accuracy. After correcting for limb darkening, this gives the stellar radius as 13.4 times the radius of the Sun.[8] The star is radiating about 85 times the luminosity of the Sun[4] and has 2.7 times the Sun's mass.[7] With its large size and low projected rotational velocity of 4 km s−1,[11] it takes about 253 days to complete a rotation.[10]

References

Template:Reflist

Template:Stars of Taurus

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  1. ↑ a b c d e Cite error: Invalid <ref> tag; no text was provided for refs named hipparcos
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  4. ↑ a b c d e f g Script error: No such module "Citation/CS1".
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  7. ↑ a b c d e Script error: No such module "Citation/CS1".
  8. ↑ a b c d Script error: No such module "Citation/CS1".
  9. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named aaa480_1_91
  10. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aaa421_241
  11. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named coapa239_1
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  13. ↑ Script error: No such module "citation/CS1".
  14. ↑ a b Script error: No such module "citation/CS1".
  15. ↑ Script error: No such module "citation/CS1".
  16. ↑ Script error: No such module "citation/CS1".
  17. ↑ Script error: No such module "citation/CS1".
  18. ↑ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
  19. ↑ Template:In lang 香港太空館 - 研究資源 - 亮星中英對照表 Template:Webarchive, Hong Kong Space Museum. Accessed on line November 23, 2010.
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