W Canis Majoris
| Observation data EpochJ2000.0EquinoxJ2000.0(ICRS) | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 07h08m03.43652s[2] |
| Declination | −11° 55′ 23.7977″[2] |
| Apparent magnitude(V) | 6.35–7.90[3] |
| Characteristics | |
| Spectral type | C6,3(N)[3] |
| B−Vcolor index | +2.55[4] |
| Variable type | Lb[3][5] |
| Astrometry | |
| Radial velocity(Rv) | 23.00[6]km/s |
| Proper motion(μ) | RA:−6.518[2]mas/yr Dec.:2.280[2]mas/yr |
| Parallax(π) | 1.8049 ± 0.1454mas[7] |
| Distance | 1,800 ± 100ly (550 ± 40pc) |
| Details | |
| Radius | 251[8][a]R☉ |
| Luminosity | 2,900[8]L☉ |
| Surface gravity(logg) | 0.0[9]cgs |
| Temperature | 2,900[9][8]K |
| Other designations | |
| Database references | |
| SIMBAD | data |
W Canis Majoris(W CMa) is acarbon starin theconstellationCanis Major.A coolstar,it has a surface temperature of around 2,900 K and a radius 251 times that of theSun,[8]with abolometricabsolute magnitudeof −4.13 and distance estimated at 443 or 445parsecs(1,444–1,450light-years) based on bolometric magnitude or radius. TheGaia Data Release 2parallaxof1.8049±0.1454milliarcsecondsimplies a distance of about 555 parsecs.
W CMa is classified as aslow irregular variablestar. Detailed analyses have found only very weak and probably spurious periods of approximately a month.[5]It is a carbon star, anasymptotic giant branchstar where carbon ands-processelements have beendredged upto the surface during thermal pulses of thehelium-burningshell.[10]
Notes[edit]
- ^Applying theStefan–Boltzmann lawwith a nominalsolareffective temperatureof 5,772K:
- .
References[edit]
- ^"ASAS All Star Catalogue".The All Sky Automated Survey.Retrieved8 December2021.
- ^abcdVan 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.S2CID18759600.
- ^abcSamus, 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.
- ^abPercy, 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): 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): 759–771.arXiv:1606.08053.Bibcode:2006AstL...32..759G.doi:10.1134/S1063773706110065.S2CID119231169.
- ^Brown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData Release 2: Summary of the contents and survey properties ".Astronomy & Astrophysics.616.A1.arXiv:1804.09365.Bibcode:2018A&A...616A...1G.doi:10.1051/0004-6361/201833051.Gaia DR2 record for this sourceatVizieR.
- ^abcdSiderud, Emelie (2020).Dust emission modelling of AGB stars.
- ^abvan 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.S2CID43847096.
- ^Herwig, Falk; Austin, Sam M. (2004). "Nuclear Reaction Rates and Carbon Star Formation".The Astrophysical Journal.613(1): L73–L76.arXiv:astro-ph/0408394.Bibcode:2004ApJ...613L..73H.doi:10.1086/424872.S2CID119462309.
