 Solution

The Stefan–Boltzmann law gives the radiated luminosityFor radiative mass loss at fixed luminosity, using mass-energy equivalence, the mass-loss magnitude and one-percent time areThe numerical constants are the external CODATA 2014 $\sigma =5.670367\times 10^{-8}\mathrm{W}{\mathrm{m}}^{-2}{\mathrm{K}}^{-4}$ and $c=299792458\mathrm{m}{\mathrm{s}}^{-1}$; years here mean 365.25 days.^[ref] This estimates radiative mass loss with the supplied radius and temperature held constant. It does not predict a real stellar lifetime or include solar-wind mass loss.