Sigma Hydrae

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Sigma Hydrae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hydra
Right ascension 8h 38m 45.4s
Declination 3° 20' 29"
Apparent magnitude (V) 4.44
Distance 353 ly
(108.28 pc)
Spectral type K1III
Other designations
5 Hydrae, HD 73471, HR 3418, SAO 116988, FK5 1224, NSV --, BD +03 2026, HIP 42402

Sigma Hydrapp (σ Hydrae, σ Hya) is the 4th-magnitude star in the constellation Hydra. Sigma Hydrae belongs to spectral class K1+III and has apparent magnitude +4.44. It is approximately 353 light years from Earth


It is also known by the proper name Minchir, and appears as Minchir es-schudscha' on Bode's large star atlas, Uranographia, which is derived from the Arabic Minkhir al-Shuja‘, "the Nostril of Hydra", for this star. The name is erroneously spelt as Al Minliar al Shuja in the Yale Bright Star Catalogue.[1].

This star, along with δ Hya (Lisan al Shudja), ε Hya, ζ Hya, η Hya and ρ Hya, 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 this star)[2]

In Chinese, 柳宿 (Liǔ Sù), meaning Willow (asterism), refers to an asterism consisting of σ Hydrae, δ Hydrae, η Hydrae, ρ Hydrae, ε Hydrae, ζ Hydrae, ω Hydrae and θ Hydrae[3] Consequently, σ Hydrae itself is known as 柳宿二 (Liǔ Sù èr, English: the Second Star of Willow.).[4]

The people of Groote Eylandt, called Unwala, "The Crab", for the star cluster including this star, δ Hya (Lisan al Shudja), ε Hya, ζ Hya, η Hya and ρ Hya.[5]


  1. ^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 249. ISBN 0-486-21079-0. Retrieved 2010-12-12. 
  2. ^ 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
  3. ^ (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.
  4. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 28 日
  5. ^ Encyclopaedia of the history of science, technology, and medicine in non-western cultures, ed. Helaine Selin, Dordrecht, Kluwer Academic Publishers, 1997, p.105.

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