Galaxy Group/Cluster

A galaxy group is a collection of about one hundred or fewer galaxies that are held together by gravitational attraction.
A galaxy cluster is a collection of galaxies that is bigger than a galaxy group. The number of galaxies in a galaxy cluster can range from hundreds to thousands of galaxies.
Galaxy groups and galaxy clusters can be contained within superclusters.
Category:Canon
Category:Cosmology
Category:Class 1
Category:Standard Branch