[问答题]
Cepheid variable stars change in lumukat um-y6 e9(h ndv7-inos+2tr8t5h v tx yoo.0pfity with a typical period of several days. The period has been found to have a defi0 poxt5 .htoyfr+28tvnite relationship with the absolute luminosity of the star. How could these stars be used to measure the distance to galaxies?
