Radiative mass loss at fixed luminosity
= Radiative mass loss at fixed luminosity
For <luminosity> $L$, <mass-energy equivalence> gives $|\dot M|=L/c^2$. Holding $L$ constant gives a time $t=fMc^2/L$ to radiate a mass fraction $f$. A <blackbody> estimate uses the <Stefan–Boltzmann law>, $L=4\pi R^2\sigma T^4$. This is a radiative-energy estimate, not a model of a star's evolving nuclear fuel or mass loss in a wind.