Beta Camelopardalis is the brightest star in the northern constellation of Camelopardalis. Its name is a Bayer designation that is Latinised from β Camelopardalis, and abbreviated Beta Cam or β Cam. This star is bright enough to be faintly visible to the naked eye, having an apparent visual magnitude of 4.02.[1] Based upon an annual parallax shift of 3.74 mas as seen from Earth, it is located at a distance of approximately 840 light-years (260 pc) from the Sun. It is moving closer with a radial velocity of −1.90 km/s[2] and is most likely a single[3] star.

This is a yellow-hued G-type supergiant/bright giant with a stellar classification of G1 Ib–IIa.[4] It is an estimated 60 million years old and is spinning with a projected rotational velocity of 11.7 km/s.[5] This is an unusually high rate of rotation for an evolved star of this type. One possible explanation is that it may have engulfed a nearby giant planet, such as a hot Jupiter.[6]

Beta Camelopardalis has 6.5 times the mass of the Sun[4] and has expanded to around 58 the Sun's radius.[7] The star is radiating 1,592 times the Sun's luminosity from its enlarged photosphere[8] at an effective temperature of 5,300 K.[4] It is a source of X-ray emission.[9]

β Cam has two visual[3] companions: a 7th-magnitude A5-class star at an angular separation of 84 arcseconds; and a 12th-magnitude star at 15 arcseconds.[10]

References

  1. ^ Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D
  2. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169
  3. ^ 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
  4. ^ Lyubimkov, Leonid S. et al. (2015). "Carbon abundance and the N/C ratio in atmospheres of A-, F- and G-type supergiants and bright giants". Monthly Notices of the Royal Astronomical Society. 446 (4): 3447. arXiv:1411.2722. Bibcode:2015MNRAS.446.3447L. doi:10.1093/mnras/stu2299
  5. ^ Rodrigues Da Silva, R. et al. (2015). "On the Nature of Rapidly Rotating Single Evolved Stars". The Astrophysical Journal. 801 (1): 54. arXiv:1503.03447. Bibcode:2015ApJ...801...54R. doi:10.1088/0004-637X/801/1/54. S2CID 119271718
  6. ^ Rodrigues da Silva, R. et al. (March 2015). "On the Nature of Rapidly Rotating Single Evolved Stars". The Astrophysical Journal. 801 (1): 6. arXiv:1503.03447. Bibcode:2015ApJ...801...54R. doi:10.1088/0004-637X/801/1/54. S2CID 119271718. 54.
  7. ^ Van Belle, G. T. et al. (2009). "Supergiant temperatures and linear radii from near-infrared interferometry". Monthly Notices of the Royal Astronomical Society. 394 (4): 1925. arXiv:0811.4239. Bibcode:2009MNRAS.394.1925V. doi:10.1111/j.1365-2966.2008.14146.x. S2CID 118372600
  8. ^ McDonald, I. et al. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352
  9. ^ Haakonsen, Christian Bernt & Rutledge, Robert E. (September 2009). "XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources". The Astrophysical Journal Supplement. 184 (1): 138–151. arXiv:0910.3229. Bibcode:2009ApJS..184..138H. doi:10.1088/0067-0049/184/1/138. S2CID 119267456
  10. ^ Mason, Brian D. et al. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920