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Suggest pagesEpsilon Hydrae
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Hydra |
| Right ascension | 8h 46m 46.6s |
| Declination | 6° 25' 8" |
| Apparent magnitude (V) | 3.38 |
| Distance | 135 ly (41.41 pc) |
| Spectral type | G5III |
| Other designations | |
Epsilon Hydrae (ε Hya, ε Hydrae) is a Class G5, third-magnitude star in the constellation Hydra. Epsilon Hydrae is a binary star with components of magnitudes 3.3 and 6.8, separated by 2.7 arcseconds. This stellar system is located about 135 light-years from Earth.
[edit] Name and etymology
This star, along with δ Hya (Lisan al Sudja), ζ Hya, η Hya, ρ Hya and σ Hya (Minhar al Shija), were Ulug Beg's Min al Azʽal, "Belonging to the Uninhabited Spot".[1]
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Min al Azʽal or Minazal were the title for five stars:δ Hya as Minazal I, η Hya as Minazal II, ε Hya as Minazal III, ρ Hya as Minazal IV and ζ Hya as Minazal V (exclude σ Hya)[2]
In Chinese, 柳宿 (Liǔ Sù), meaning Willow (asterism), refers to an asterism consisting of ε Hydrae, δ Hydra, σ Hydrae, η Hydrae, ρ Hydrae, ζ Hydrae, ω Hydrae and θ Hydrae[3] Consequently, ε Hydrae itself is known as 柳宿五 (Liǔ Sù wǔ, English: the Fifth Star of Willow.)[4]
The people of Groote Eylandt called Unwala, "The Crab", for the star cluster including this star, δ Hya (Lisan al Sudja), ζ Hya, η Hya, ρ Hya and σ Hya (Minhar al Shija).[5]
[edit] References
- ^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 249. ISBN 0486210790. http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Hydra*.html. Retrieved 2010-12-12.
- ^ Jack W. Rhoads - Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology; November 15, 1971
- ^ (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 9789867332257.
- ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 28 日
- ^ p. 105, Encyclopaedia of the history of science, technology, and medicine in non-western cultures, Helaine Selin, Dordrecht, Kluwer Academic Publishers, 1997.
- "HD 74874 -- Variable Star". SIMBAD Astronomical Database. http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=epsilon+hydrae&NbIdent=1&Radius=10&Radius.unit=arcmin&CooFrame=FK5&CooEpoch=2000&CooEqui=2000&output.max=all&o.catall=on&output.mesdisp=N&Bibyear1=1983&Bibyear2=2005&Frame1=FK5&Frame2=FK4&Frame3=G&Equi1=2000.0&Equi2=1950.0&Equi3=2000.0&Epoch1=2000.0&Epoch2=1950.0&Epoch3=2000.0. Retrieved 2006-11-05.
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