W Canis Majoris

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. 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.