[填空题]
Stars located in a certain g7 eyzcrox.+) 1wlx/ lcluster are8m ap 1ho*19si;9n,asfkv ltd assumed to be about the same distance from us. Two su*,nm8kaasf;o9t 1h9isld1v p ch stars have spectra that peak at $\lambda_1 = 500\ \text{nm}$ 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.]
