Evolved stars with initial mass larger than about 20Mo. Their effective temperature ranges from about 30,000 to 200,000K. They have strong stellar winds at high velocity. They show broad emission lines of He, C, N, O, Si. They are at the late stages of massive star evolution, after the red (less than 40Mo) or blue supergiant phases. They are thought to be the progenitors of Type Ib and Ic supernovae.

-- CecileLoup - 2014-02-20