Norma Cluster

The Norma Cluster (ACO 3627 or Abell 3627) is a rich of galaxies near the center of the Great Attractor. 
It is both nearby and bright; but it is difficult to observe because it is in the Zone of Avoidance. This is a region near the plane of the Milky Way, which obscures our view. The cluster is hidden by interstellar dust at optical wavelengths. Its mass is estimated to be on the order of 1015 solar masses.