W Canis Majoris
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 07h 08m 03.43652s[1] |
| Declination | −11° 55′ 23.7977″[1] |
| Apparent magnitude (V) | 6.35 - 7.90[2] |
| Characteristics | |
| Spectral type | C6,3(N)[2] |
| B−V color index | +2.55[3] |
| Variable type | Lb[2][4] |
| Astrometry | |
| Radial velocity (Rv) | 23.00[5] km/s |
| Proper motion (μ) | RA: −5.55[1] mas/yr Dec.: 2.74[1] mas/yr |
| Parallax (π) | 0.39 ± 0.52[1] mas |
| Distance | 1,444 - 1,450[6] ly (443 - 445[6] pc) |
| Details | |
| Radius | 234[6] R☉ |
| Luminosity | 3,560[6] L☉ |
| Surface gravity (log g) | 0.0[6] cgs |
| Temperature | 2,900[6] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
W Canis Majoris is a carbon star in the constellation Canis Major. A cool star, it has a surface temperature of around 2,900 K and a radius 234 times that of the sun, with a bolometric absolute magnitude of −4.13 and distance estimated at 443 or 445 parsecs (1444-1450) light-years based on bolometric magnitude or radius.
W CMa is classified as an irregular star. Detailed analyses have found only very weak and probably spurious periods of approximately a month.[4] It is a carbon star, an asymptotic giant branch star where carbon and s-process elements have been dreged up to the surface during thermal pulses of the helium burning shell.[7]
References
- 1 2 3 4 5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- 1 2 3 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ↑ Alksnis, A.; Balklavs, A.; Dzervitis, U.; Eglitis, I. (1998). "Absolute magnitudes of carbon stars from HIPPARCOS parallaxes". Astronomy and Astrophysics. 338: 209. Bibcode:1998A&A...338..209A.
- 1 2 Percy, J. R.; Terziev, E. (2011). "Studies of "Irregularity" in Pulsating Red Giants. III. Many More Stars, an Overview, and Some Conclusions". The Journal of the American Association of Variable Star Observers. 39: 1. Bibcode:2011JAVSO..39....1P.
- ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
- 1 2 3 4 5 6 van Belle, Gerard T.; Paladini, Claudia; Aringer, Bernhard; Hron, Josef; et al. (2013). "The PTI Carbon Star Angular Size Survey: Effective Temperatures and Non-sphericity". The Astrophysical Journal. 775 (1): article id. 45, 19 pp. arXiv:1307.6585
. Bibcode:2013ApJ...775...45V. doi:10.1088/0004-637X/775/1/45. - ↑ Herwig, Falk; Austin, Sam M. (2004). "Nuclear Reaction Rates and Carbon Star Formation". The Astrophysical Journal. 613: L73. arXiv:astro-ph/0408394. Bibcode:2004ApJ...613L..73H. doi:10.1086/424872.
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