Xi2 Canis Majoris is an astrometric binary[4] star system in the southern constellation of Canis Major. Its name is Latinized from ξ2 Canis Majoris, and abbreviated Xi2 CMa or ξ2 CMa. With an apparent visual magnitude of +4.54,[2] it is bright enough to be visible to the naked eye. Based upon an annual parallax shift of 8.03 mas,[1] the system is approximately 410 light years distant from Earth. It is receding with a radial velocity of +22 km/s.[1]
The binary nature of this system was determined based on changes in the proper motion of the visible component.[11] W. Buscombe (1962) gave the white-hued primary a stellar classification of A0 V,[3] indicating it is an A-type main-sequence star. However, N. Houk and M. Smith-Moore (1978) list it with a class of A0 III,[5] which would match a more evolved giant star, also of the A-type. It is 339[6] million years old with a high rate of spin, having a projected rotational velocity of 145 km/s. This is giving the star an equatorial bulge that is about 12% wider than the polar diameter.[9] The star has four[7] times the mass of the Sun and six times the Sun's girth. It is radiating 247 times the Sun's luminosity from its photosphere at an effective temperature of 9,381 K.[8]
References
- ^ a b c d e f g Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875.
Gaia DR3 record for this source at VizieR.
- ^ 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): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b Buscombe, W. (1962), "Spectral classification of Southern fundamental stars", Mount Stromlo Observatory Mimeogram, 4: 1, Bibcode:1962MtSOM...4....1B.
- ^ 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, S2CID 14878976.
- ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
- ^ a b c Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID 119108982.
- ^ a b Kervella, Pierre; et al. (2019), "Stellar and substellar companions of nearby stars from Gaia DR2: Binarity from proper motion anomaly", Astronomy & Astrophysics, 623: A72, arXiv:1811.08902, Bibcode:2019A&A...623A..72K, doi:10.1051/0004-6361/201834371, ISSN 0004-6361.
- ^ a b c d McDonald, I.; et al. (October 2017), "Fundamental parameters and infrared excesses of Tycho-Gaia stars", Monthly Notices of the Royal Astronomical Society, 471: 770–791, arXiv:1706.02208, Bibcode:2017MNRAS.471..770M, doi:10.1093/mnras/stx1433, ISSN 0035-8711. Xi2 Canis Majoris' database entry at VizieR.
- ^ a b Belle, G. T. (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.
- ^ "xi02 CMa", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-09-05.
- ^ Makarov, V. V.; Kaplan, G. H. (May 2005), "Statistical Constraints for Astrometric Binaries with Nonlinear Motion", The Astronomical Journal, 129 (5): 2420–2427, Bibcode:2005AJ....129.2420M, doi:10.1086/429590.
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