A large group of stars is called a galaxy. Many people believe that it is a constellation but that is a group of stars that for a perticular picture.+++ I'd say cluster: a galaxy consists of a huge mass of many millions, or thousands of millions, of individual and clustered stars, and clouds of gas and dust. large group of stars is called a galaxy. Many people believe that it is a constellation but that is a group of stars that for a perticular picture.