Omega Herculis

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Kajam, ω Her
Hercules Historical View.png
Historical view of the Hercules constellation showing the star Kajam (ω Her) as "the club" in the hero's right hand.
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
Right ascension 16h 25m 24.9533s[1]
Declination 14° 01′ 59.770″[1]
Apparent magnitude (V) 4.5821[2]
Spectral type B9p Cr[2]
U−B color index 0.01[3]
B−V color index +0.00[3]
Radial velocity (Rv) -5.9[1] km/s
Proper motion (μ) RA: 39.39[1] mas/yr
Dec.: -59.89[1] mas/yr
Parallax (π) 13.87 ± 0.94[4] mas
Distance 240 ± 20 ly
(72 ± 5 pc)
Absolute magnitude (MV) 0.29
Other designations
Kajam, Kujam, Cujam, ω Her, 24 Her, HR 6117, BD +14° 3049, HD 148112, FK5 613, HIP 80463, SAO 102153, GC 22090, CCDM J16254+1402AB
Database references

Coordinates: Sky map 16h 25m 24.953s, +14° 01′ 59.77″

Omega Herculis (ω Her, ω Herculis) is a star in the constellation Hercules. It has the traditional name Kajam ("club") (also written as Cajam, Cujam).[5]

In Chinese, (Dǒu), meaning Dipper for Liquid, refers to an asterism consisting of ω Herculis, 49 Serpentis, 13 Herculis, 29 Herculis and 33 Herculis.[6] Consequently, ω Herculis itself is known as 斗一 (Dǒu yī, English: the First Star of Dipper for Liquid.)[7]

Omega Herculis was a latter designation of 51 Serpentis.[8]


Omega Herculis belongs to spectral class B9pCr and has apparent magnitude +4.58. It is approximately 240 light years from Earth.

See also[edit]


  1. ^ a b c d e "SIMBAD query result:V* ome Her -- Variable Star of alpha2 CVn type". Centre de Données astronomiques de Strasbourg. Retrieved 2010-09-26. 
  2. ^ a b van Leeuwen, F (November 2007). "Hipparcos, the New Reduction". Astronomy and Astrophysics (Centre de Données astronomiques de Strasbourg) 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. VizieR: Detailed Page. 
  3. ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV data. (SIMBAD). Bibcode:1986EgUBV........0M. 
  4. ^ Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E. et al. (1997). "The HIPPARCOS Catalogue". Astronomy and Astrophysics 323: L49–L52. Bibcode:1997A&A...323L..49P. 
  5. ^ Vonnegut, Kurt. "Constellations: Hercules 'the Strongman'". The BBC (British Broadcasting Corporation). Retrieved 2010-11-14. 
  6. ^ (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.
  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.
  8. ^ Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy 18 (3): 209. Bibcode:1987JHA....18..209W.