Astronomy:Xi2 Canis Majoris

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Short description: Star in the constellation Canis Major


Xi2 Canis Majoris
Observation data
Equinox J2000.0]] (ICRS)
Constellation Canis Major
Right ascension  06h 35m 03.38859s[1]
Declination −22° 57′ 53.2913″[1]
Apparent magnitude (V) +4.54[2]
Characteristics
Spectral type A0 V[3][4] or A0 III[5]
U−B color index −0.01[2]
B−V color index −0.06[2]
Astrometry
Radial velocity (Rv)+26.0±4.2[6] km/s
Proper motion (μ) RA: +15.437[1] mas/yr
Dec.: +18.682[1] mas/yr
Parallax (π)8.3465 ± 0.2721[1] mas
Distance390 ± 10 ly
(120 ± 4 pc)
Absolute magnitude (MV)+0.94[7]
Details
Radius2.7[8] R
Luminosity224[9] L
Temperature8,799[9] K
Rotational velocity (v sin i)145[10] km/s
Age339[7] Myr
Other designations
ξ2 CMa, 5 Canis Majoris, BD−22°1458, FK5 249, GC 8577, HD 46933, HIP 31416, HR 2414, SAO 171982[11]
Database references
SIMBADdata

Xi2 Canis Majoris, which is Latinized from ξ2 Canis Majoris, is an astrometric binary[4] star system in the southern constellation of Canis Major. With an apparent visual magnitude of +4.54,[2] it is visible to the naked eye. Based upon an annual parallax shift of 8.35 mas,[1] the system is approximately 390 light years distant from Earth. It is receding with a radial velocity of +26 km/s.[6]

The binary nature of this system was determined based on changes in the proper motion of the visible component.[12] Buscombe (1962) gave the white-hued primary a stellar classification of A0 V,[3] indicating it is an A-type main-sequence star. However, Houk and 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[7] million years old with a high rate of spin, having a projected rotational velocity of 145 km/s.[10] The star is radiating 224[9] times the Sun's luminosity from its photosphere at an effective temperature of 8,799 K.[9]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. 3.0 3.1 Buscombe, W. (1962), "Spectral classification of Southern fundamental stars", Mount Stromlo Observatory Mimeogram 4: 1, Bibcode1962MtSOM...4....1B. 
  4. 4.0 4.1 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  5. 5.0 5.1 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1988mcts.book.....H. 
  6. 6.0 6.1 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  7. 7.0 7.1 7.2 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode2012AstL...38..694G. 
  8. Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy & Astrophysics 367: 521–24, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  9. 9.0 9.1 9.2 9.3 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode2012MNRAS.427..343M. 
  10. 10.0 10.1 Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review 20 (1): 51, doi:10.1007/s00159-012-0051-2, Bibcode2012A&ARv..20...51V. 
  11. "xi02 CMa". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=xi02+CMa. 
  12. Makarov, V. V.; Kaplan, G. H. (May 2005), "Statistical Constraints for Astrometric Binaries with Nonlinear Motion", The Astronomical Journal 129 (5): 2420–2427, doi:10.1086/429590, Bibcode2005AJ....129.2420M.