1. Two stars, X and Y, have luminosities in the ratio LX:LY=500 . If the ratio of their surface temperatures TX:TY=20 , calculate the ratio of their radii, RX:RY .
(1) Two stars, X and Y, have luminosities in the ratio LX:LY=500 . If the ratio of their surface temperatures TX:TY=20 , calculate the ratio of their radii, RX:RY .
(2) The star Rigel, in the constellation of Orion, is about 70 times the radius of our Sun. The star Betelgeuse, also in Orion, has a radius about 1100 times that of our Sun. The surface temperature of Rigel is about twice that of our Sun and the surface temperature of Betelgeuse is about three-fifths that of our Sun. Show that the luminosity of Betelgeuse is about twice that of Rigel.