The Galaxy Cluster Abell 2151 in Constellation Hercules
The galaxy cluster Abell 2151 in the constellation Hercules, therefore also known as the Hercules cluster, has an extension of approx. 1° and is located at a distance of approx. 500 light years. Unlike other clusters, it has no central galaxy, and contains several interacting galaxy systems. It was first described by Harlow Shapley in 1933.