Epsilon Virginis
 Location of ε Virginis (circled) |
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| Observation data Epoch J2000.0 Equinox J2000.0 |
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|---|---|
| Constellation | Virgo |
| Right ascension | 13h 02m 10.6s[1] |
| Declination | +10° 57′ 33″[1] |
| Apparent magnitude (V) | +2.83[1] |
| Characteristics | |
| Spectral type | G8 III[1] |
| B−V color index | +0.94[2] |
| Astrometry | |
| Radial velocity (Rv) | -14.0[1] km/s |
| Proper motion (μ) | RA: -275.05[1] mas/yr Dec.: +19.96[1] mas/yr |
| Parallax (π) | 31.9 ± 0.87[1] mas |
| Distance | 102 ± 3 ly (31.3 ± 0.9 pc) |
| Absolute magnitude (MV) | 0.37 ± 0.06[3] |
| Details | |
| Mass | 2.64 ± 0.11[3] M☉ |
| Radius | 10.6 ± 0.3[4] R☉ |
| Luminosity | 77[2] L☉ |
| Surface gravity (log g) | 2.71 ± 0.04[3] |
| Temperature | 5,086[3] K |
| Metallicity [Fe/H] | +0.09[3] dex |
| Rotation | 173[5] |
| Rotational velocity (v sin i) | 2.3[6] km/s |
| Age | 0.56 ± 0.09[3] Gyr |
| Other designations | |
Epsilon Virginis (ε Vir, ε Virginis) is a star in the zodiac constellation Virgo. It has the traditional name Vindemiatrix, which comes from Greek through Latin and means Grape Gatherer.
Vindemiatrix is a yellow giant star of apparent magnitude 2.83 and spectral class G8 III about 102 light years from Earth. It has a luminosity 83 times that of the sun with a surface temperature of 4990 kelvin.[7] Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[8]
There is evidence that Vindemiatrix is part of the Hyades group, associated with the cluster of that name in the constellation Taurus.[citation needed]
[edit] Etymology
The traditional names Vindemiatrix and Vindemiator are from Latin vindēmiātrix, vindēmitor "the grape-harvestress". Additional medieval names are Almuredin, Alaraph, Provindemiator, Protrigetrix, and Protrygetor.
This star, along with β Vir(Zavijava), γ Vir (Porrima), η Vir (Zaniah) and δ Vir, (Auva), were Al ʽAwwāʼ, the Barker.[9]
In Chinese, 太微左垣 (Tài Wēi Zuǒ Yuán), meaning Left Wall of Supreme Palace Enclosure, refers to an asterism consisting of ε Virginis, η Virginis, γ Virginis, δ Virginis and α Comae Berenices.[10] Consequently, ε Virginis itself is known as 太微左垣四 (Tài Wēi Zuǒ Yuán sì, English: the Fourth Star of Left Wall of Supreme Palace Enclosure.)[11], representing 東次將 (Dōngcìjiāng), meaning The Second Eastern General[12]. 東次將 (Dōngcìjiāng), westernized into Tsze Tseang by R.H. Allen and the meaning is "the Second General"[13]
[edit] References
- ^ a b c d e f g h Database entry for Epsilon Viginis, SIMBAD. Accessed online May 10, 2010.
- ^ a b Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics 352: 495–507, Bibcode 1999A&A...352..495M
- ^ a b c d e f da Silva, L. et al. (November 2006), "Basic physical parameters of a selected sample of evolved stars", Astronomy and Astrophysics 458 (2): 609–623, Bibcode 2006A&A...458..609D, doi:10.1051/0004-6361:20065105
- ^ Nordgren, Tyler E. et al. (December 1999), "Stellar Angular Diameters of Late-Type Giants and Supergiants Measured with the Navy Prototype Optical Interferometer", The Astronomical Journal 118 (6): 3032-3038, Bibcode 1999AJ....118.3032N, doi:10.1086/301114
- ^ Setiawan, J. et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics 421: 241-254, Bibcode 2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1
- ^ Pizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics 361: 614–628, Bibcode 2000A&A...361..614P
- ^ Kaler, james B., "Vindemiatrix", Stars, http://stars.astro.illinois.edu/sow/vindemiatrix.html, retrieved 2011-01-12
- ^ Garrison, R. F. (December 1993), "Anchor Points for the MK System of Spectral Classification", Bulletin of the American Astronomical Society 25: 1319, Bibcode 1993AAS...183.1710G, http://www.astro.utoronto.ca/~garrison/mkstds.html, retrieved 2012-02-04
- ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc, p. 469, ISBN 0486210790, http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Virgo*.html, retrieved 2010-12-12
- ^ (Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ^ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ^ (Chinese) English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Virgo
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