Epsilon Virginis Explained

Epsilon Virginis (ε Virginis, abbreviated Epsilon Vir, ε Vir), formally named Vindemiatrix,[1] is a star in the zodiac constellation of Virgo. The apparent visual magnitude of this star is +2.8, making it the third-brightest member of Virgo. Based upon parallax measurements made by the Gaia spapecraft, Vindemiatrix lies at a distance of about 108abbr=offNaNabbr=off from the Sun, give or take 0.7light-years.

Stellar properties

Vindemiatrix is a giant star with a stellar classification of G8 III. With 2.7 times the mass of the Sun and at an age of 700 million years,[2] it has reached a stage in its evolution where the hydrogen fuel in its core is exhausted. It is believed to be a red clump star; a red giant star fusing helium into carbon in its core surrounded by a shell fusing hydrogen into helium. As a result, it has expanded to eleven times the Sun's size and is now radiating around 91 times as much luminosity as the Sun. This energy is being emitted from its outer atmosphere at an effective temperature of 5,071 K, which gives it the yellow-hued glow of a G-type star. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.

This star is a likely member of the thin disk population and the orbit departs by no more than 60pc from the galactic plane.

Nomenclature

ε Virginis (Latinised to Epsilon Virginis) is the star's Bayer designation.

It bore the traditional names Vindemiatrix and Vindemiator, which come from Greek through the Latin vindēmiātrix, vindēmiātor meaning 'the grape-harvestress'. Additional medieval names are Almuredin,[3] Alaraph, Provindemiator, Protrigetrix and Protrygetor. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[4] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[5] included a table of the first two batches of names approved by the WGSN; which included Vindemiatrix for this star.

This star, along with Beta Virginis (Zavijava), Gamma Virginis (Porrima), Eta Virginis (Zaniah) and Delta Virginis (Minelauva), were Al ʽAwwāʼ, which is Arabic for 'the Barker'.

In Chinese, Chinese: 太微左垣 (Chinese: Tài Wēi Zuǒ Yuán), meaning Left Wall of Supreme Palace Enclosure, refers to an asterism consisting of Epsilon Virginis, Eta Virginis, Gamma Virginis, Delta Virginis and Alpha Comae Berenices.[6] Consequently, the Chinese name for Epsilon Virginis itself is Chinese: 太微左垣四 (Chinese: Tài Wēi Zuǒ Yuán sì, English: the Fourth Star of Left Wall of Supreme Palace Enclosure.),[7] representing Chinese: 東次將 (Chinese: Dōngcìjiāng), meaning The Second Eastern General.[8] 東次將 (Dōngcìjiāng), westernized into Tsze Tseang by R.H. Allen and the meaning is "the Second General".[9]

Notes and References

  1. Web site: IAU Catalog of Star Names . 28 July 2016.
  2. Howes . Louise M. . Lindegren . Lennart . Feltzing . Sofia . Church . Ross P. . Bensby . Thomas . 2019-02-01 . Estimating stellar ages and metallicities from parallaxes and broadband photometry: successes and shortcomings . Astronomy & Astrophysics . en . 622 . A27 . 10.1051/0004-6361/201833280 . 0004-6361. 1804.08321 .
  3. Book: Kunitzsch . Paul . Smart . Tim . 2006 . 2nd rev. . A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations . Sky Pub . Cambridge, Massachusetts . 978-1-931559-44-7.
  4. Web site: IAU Working Group on Star Names (WGSN). 22 May 2016.
  5. Web site: Bulletin of the IAU Working Group on Star Names, No. 1 . 28 July 2016.
  6. 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, .
  7. 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.
  8. English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name, Hong Kong Space Museum. Accessed on line November 23, 2010.
  9. https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Virgo*.html Richard Hinckley Allen: Star Names — Their Lore and Meaning: Virgo