Wolf–Rayet Star

Wolf–Rayet Star

Wolf–Rayet stars (often referred to as WR stars) are evolved, massive stars (over 20 solar masses initially) which are losing mass rapidly by means of a very strong stellar wind, with speeds up to 2000 km/s. While our own Sun loses approximately 10−14 solar masses every year, Wolf–Rayet stars typically lose 10−5 solar masses a year.

Wolf–Rayet stars are extremely hot, with surface temperatures in the range of 30,000 K to around 200,000K. They are also highly luminous, from tens of thousands to several million times the bolometric luminosity of the sun, although not exceptionally bright visually since most of their output is in far ultraviolet and even soft X-rays.