Omega Eridani (ω Eri) is a single[10] star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude is 4.37.[2] The distance to this star, as determined by the parallax method, is around 235 light years.

It is an A-type subgiant star with a stellar classification of A9 IVn,[3] where the 'n' suffix indicates a broad ("nebulous") absorption due to rotation. The projected rotational velocity is 186[8] km/s.[8] This gives the star an oblate shape with an equator that is 13% wider than the polar radius. The angular size of Omega Eridani is 0.87 mas.[11] At an estimated distance of the star, this yields a physical size of around 6.7 times the radius of the Sun.[6]

Omega Eridani was long thought to be a is a single-lined spectroscopic binary system, with an orbital period of 3,057 days (8.4 years) and an eccentricity of 0.46.[12] However, newer and higher-quality radial velocity observations find no evidence for a companion, casting serious doubt on the status of Omega Eridani as a binary star.[10]

References

  1. ^ a b c d e van Leeuwen, F. (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. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (July 1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
  4. ^ De Bruijne, J. H. J.; Eilers, A.-C. (2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: A61, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347.
  5. ^ a b c Giridhar, S.; et al. (August 2013), "Identification of metal-poor stars using the artificial neural network", Astronomy & Astrophysics, 556: 11, arXiv:1307.6308, Bibcode:2013A&A...556A.121G, doi:10.1051/0004-6361/201219918, S2CID 118316149, A121.
  6. ^ a b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
  7. ^ a b 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. ^ a b c Royer, F.; et al. (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, S2CID 18475298.
  9. ^ "* ome Eri -- Spectroscopic binary". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-11-03.{{cite web}}: CS1 maint: postscript (link)
  10. ^ a b Merle, T.; Pourbaix, D.; Jorissen, A.; Siopis, C.; Eck, S. Van; Winckel, H. Van (2024-04-01). "Update of SB9 orbits using HERMES/Mercator radial velocities". Astronomy & Astrophysics. 684: A74. arXiv:2312.09151. Bibcode:2024A&A...684A..74M. doi:10.1051/0004-6361/202345918. ISSN 0004-6361.
  11. ^ van Belle, Gerard T., Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474.
  12. ^ Abt, Helmut A.; Boonyarak, Chayan (November 2004), "Tidal Effects in Binaries of Various Periods", The Astrophysical Journal, 616 (1): 562–566, Bibcode:2004ApJ...616..562A, doi:10.1086/423795.
Allikas: https://en.wikipedia.org/wiki/Omega_Eridani
No tags for this post.