12 mayo 2015
To measure distances in the Universe, astronomers use Cepheids, a family of variable stars whose luminosity varies with time. Their role as distance calibrators has brought them attention from researchers for more than a century. While it was thought that nearly everything was known about the prototype of Cepheids, named Delta Cephei, a team of researchers have now discovered that this star is not alone, but that it has a hidden companion.
http://feeds.sciencedaily.com/~r/sciencedaily/~3/QM3lqLYtmJ8/150512074933.htm
