Omega Aurigae

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Omega Aurigae
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension  04h 59m 15.40974s[1]
Declination +37° 53′ 24.8816″[1]
Apparent magnitude (V) 4.95[2]
Evolutionary stage main sequence[3]
Spectral type A1 V[4]
U−B color index +0.01[2]
B−V color index +0.05[2]
R−I color index 0.03
Radial velocity (Rv)+5[5] km/s
Proper motion (μ) RA: +46.35[1] mas/yr
Dec.: −97.80[1] mas/yr
Parallax (π)20.5 ± 0.94[1] mas
Distance159 ± 7 ly
(49 ± 2 pc)
Absolute magnitude (MV)+1.34[6]
Mass2.29±0.04[3] M
Radius2.1–2.7[7] R
Luminosity27[6] L
Surface gravity (log g)4.33[4] cgs
Temperature9,230[4] K
Metallicity [Fe/H]–0.12[4] dex
Rotational velocity (v sin i)107[8] km/s
Other designations
ω Aur, 4 Aur, BD+37°1005, HD 31647, HIP 23179, HR 1592, SAO 57548, WDS J04593+3753AB[9]
Database references

Omega Aurigae, Latinized from ω Aurigae, is the Bayer designation for a double star[10] in the northern constellation of Auriga. Its apparent magnitude is 4.95,[2] which is bright enough to be seen with the naked eye. The distance to this system, as determined using parallax measurements, is approximately 159 light-years (49 parsecs).[1]

This is an A-type main sequence star with a stellar classification of A1 V,[4] it has 2.3[3] times the mass of the Sun and is radiating 27[6] times the Sun's luminosity from its photosphere at an effective temperature of 9,230 K.[4] The object displays an infrared excess, suggesting an orbiting debris disk with a temperature of 20 K at a mean radius of 932.40 AU from the host star.[11] It has a magnitude 8.18 companion at an angular separation of 4.99 arcseconds.[10] The system is an X-ray source with a luminosity of 16.57×1029 ergs s−1.[12]


  1. ^ a b c d e f van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. Note: see VizieR catalogue I/311.
  2. ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.
  3. ^ a b c Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.
  4. ^ a b c d e f Hill, G. M. (February 1995), "Compositional differences among the A-type stars. 2: Spectrum synthesis up to V sin i = 110 km/s", Astronomy and Astrophysics, 294 (2): 536–546, Bibcode:1995A&A...294..536H.
  5. ^ Wilson, Ralph Elmer (1953), General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
  6. ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
  7. ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  8. ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
  9. ^ "* ome Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-24.
  10. ^ a b Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
  11. ^ Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series, 225 (1): 24, arXiv:1606.01134, Bibcode:2016ApJS..225...15C, doi:10.3847/0067-0049/225/1/15, 15.
  12. ^ Makarov, Valeri V. (October 2003), "The 100 Brightest X-Ray Stars within 50 Parsecs of the Sun", The Astronomical Journal, 126 (4): 1996–2008, Bibcode:2003AJ....126.1996M, doi:10.1086/378164.

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