Omega Virginis

Omega Virginis (ω Vir, ω Virginis) is a solitary[2] star in the zodiac constellation Virgo. It has an apparent visual magnitude of +5.22,[2] which is bright enough to be faintly visible to the naked eye. Based upon an annual stellar parallax shift of 6.56 milliarcseconds,[1] it is located about 500 light years from the Sun.

ω Virginis
Location of ω Virginis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Virgo
Right ascension 11h 38m 27.60727s[1]
Declination +08° 08′ 03.4663″[1]
Apparent magnitude (V) +5.22[2]
Characteristics
Spectral type M4 III[2]
U−B color index +1.63[3]
B−V color index +1.60[3]
Astrometry
Radial velocity (Rv)+5.13±0.52[4] km/s
Proper motion (μ) RA: −3.89[1] mas/yr
Dec.: +5.30[1] mas/yr
Parallax (π)6.56 ± 0.36[1] mas
Distance500 ± 30 ly
(152 ± 8 pc)
Absolute magnitude (MV)+0.2[5]
Details
Radius70[6] R☉
Luminosity1,515[7] L☉
Surface gravity (log g)0.8[5] cgs
Temperature3,490[7] K
Metallicity [Fe/H]−0.08[5] dex
Other designations
ω Vir, 1 Virginis, BD+08°2532, FK5 2932, HD 101153, HIP 56779, HR 4483, SAO 118965[8]
Database references
SIMBADdata

This is a red giant star with a stellar classification of M4 III.[2] It is a semiregular variable with a brightness that varies over an amplitude of 0.m28 with periods of 30 and 275 days.[9] After evolving away from the main sequence it has expanded to around 70 times the solar radius,[6] and now shines with 1,515 times the luminosity of the Sun.[7] The effective temperature of the outer atmosphere is 3,490 K.[7]

References
  1. 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, S2CID 18759600.
  2. 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, S2CID 14878976.
  3. Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.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. Famaey, B.; et al. (2009). "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations". Astronomy and Astrophysics. 498 (2): 627–640. arXiv:0901.0934. Bibcode:2009A&A...498..627F. doi:10.1051/0004-6361/200810698. S2CID 18739721.
  5. Smith, V.V.; Lambert, D.L. (1986), "The chemical composition of red giants. II - Helium burning and the s-process in the MS and S stars", Astrophysical Journal, 311: 843–863, Bibcode:1986ApJ...311..843S, doi:10.1086/164823
  6. 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 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  7. McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  8. "* ome Vir". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-09-19.
  9. Glass, I. S.; Van Leeuwen, F. (2007), "Semiregular variables in the solar neighbourhood", Monthly Notices of the Royal Astronomical Society, 378 (4): 1543–1549, arXiv:0704.3150, Bibcode:2007MNRAS.378.1543G, doi:10.1111/j.1365-2966.2007.11903.x, S2CID 14332208.
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