[填空题]
Stars located in a certain clust 52ek:w)wva nc: rb-g ne)(pwber are assumed sp1 k f+-s(jhzk2 rzo0to be about the same distance from us. Two such stars have spectra that peak a kp0s-r2ok+f( zzh 1sjt $\lambda_1 = 500\ \text{nm}$ and $\lambda_2 = 700\ \text{nm}$, and the ratio of their apparent brightness is $l_1/l_2 = 0.091$. Estimate their relative sizes (give ratio of their diameters). [Hint: use the Stefan-Boltzmann equation, Eq. 14–5.]
