W Canis Majoris

W Canis Majoris

A visual band light curve for W Canis Majoris, plotted from All Sky Automated Survey data.[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Canis Major
Right ascension 07h 08m 03.43652s[2]
Declination −11° 55′ 23.7977″[2]
Apparent magnitude (V) 6.35–7.90[3]
Characteristics
Spectral type C6,3(N)[3]
B−V color 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 ± 0.1454 mas[7]
Distance1,800 ± 100 ly
(550 ± 40 pc)
Details
Radius251[8][a] R☉
Luminosity2,900[8] L☉
Surface gravity (log g)0.0[9] cgs
Temperature2,900[9][8] K
Other designations
W CMa, BD−11° 1805, HIP 34413, HD 54361, SAO 152427
Database references
SIMBADdata

W Canis Majoris (W CMa) 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 251 times that of the Sun,[8] with a bolometric absolute magnitude of −4.13 and distance estimated at 443 or 445 parsecs (1,444–1,450 light-years) based on bolometric magnitude or radius. The Gaia Data Release 2 parallax of 1.8049±0.1454 milliarcseconds implies a distance of about 555 parsecs.

W CMa is classified as a slow irregular variable star. Detailed analyses have found only very weak and probably spurious periods of approximately a month.[5] It is a carbon star, an asymptotic giant branch star where carbon and s-process elements have been dredged up to the surface during thermal pulses of the helium-burning shell.[10]

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  8. ^ a b c d Cite error: The named reference dust_agb was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference vanBelle13 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference herwig was invoked but never defined (see the help page).


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