Bellatrix, an aa kent bi its Bayer designation Gamma Orionis (γ Ori, γ Orionis), is the third brichtest starn in the constellation Orion, 5° richt o the reid giant α Ori (Betelgeuse).

Bellatrix (γ Orionis)
Diagram showing starn poseetions an boondaries o the Orion constellation an its surroondins
Cercle rouge 100%.svg
Location of γ Orionis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
Pronunciation /ˈbɛlətrɪks/
Richt ascension 05h 25m 07.86325s[1]
Declination +06° 20′ 58.9318″[1]
Apparent magnitude (V) 1.64[2]
Spectral type B2 III[3]
U−B colour index –0.86[2]
B−V colour index –0.21[2]
Variable teep Eruptive[citation needit]
Radial velocity (Rv)+18.2[4] km/s
Proper motion (μ) RA: –8.11[1] mas/yr
Dec.: –12.88[1] mas/yr
Parallax (π)12.92 ± 0.52[1] mas
Distance250 ± 10 ly
(77 ± 3 pc)
[5] M
Radius6[6] R
Luminosity~6,400[7] L
Surface gravity (log g)3.60[8] cgs
Temperatur22,000[8] K
Metallicity [Fe/H]–0.25[9] dex
Rotational velocity (v sin i)46 ± 8[8] km/s
[5] Myr
Ither designations
Bellatrix, γ Orionis, Amazon Star, warrioress, 24 Ori, Al Najid, HR 1790, BD +06°919, HD 35468, SAO 112740, FK5 201, HIP 25336.[10]


  1. 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  2. 2.0 2.1 2.2 Crawford, D. L.; Barnes, J. V.; Golson, J. C. (December 1971), "Four-color, Hbeta, and UBV photometry for bright B-type stars in the northern hemisphere", Astronomical Journal, 76: 1058–1071, Bibcode:1971AJ.....76.1058C, doi:10.1086/111220
  3. Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics, 11: 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333
  4. Wilson, R. E. (1953), General Catalogue of Stellar Radial Velocities, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W
  5. 5.0 5.1 Janson, Markus; et al. (August 2011), "High-contrast Imaging Search for Planets and Brown Dwarfs around the Most Massive Stars in the Solar Neighborhood", The Astrophysical Journal, 736 (2): 89, arXiv:1105.2577, Bibcode:2011ApJ...736...89J, doi:10.1088/0004-637X/736/2/89
  6. Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3 ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
  7. Kaler, James B., "BELLATRIX (Gamma Orionis)", Stars, University of Illinois, retrieved 2012-12-27
  8. 8.0 8.1 8.2 Lefever, K.; et al. (June 2010), "Spectroscopic determination of the fundamental parameters of 66 B-type stars in the field-of-view of the CoRoT satellite", Astronomy and Astrophysics, 515: A74, arXiv:0910.2851, Bibcode:2010A&A...515A..74L, doi:10.1051/0004-6361/200911956
  9. Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209
  10. "BELLATRIX -- Variable Star", SIMBAD, Centre de Données astronomiques de Strasbourg

Coordinates:   05h 25m 07.9s, +06° 20′ 59″