Abell catalogue of galaxy clusters The Abell catalogue, or Catalog of Rich Clusters of Galaxies, is comprised of 5,250 galaxy clusters for both northern and southern hemispheres. Clusters with an S prefix denote southern hemisphere location. Abell 1 - Abell 500 Abell 501 - Abell 1000 Abell 1001 - Abell 1500 Abell 1501 - Abell 2000 Abell 2001 - Abell 2500 Abell 2501 - Abell 3000 Abell 3001 - Abell 3500 Abell 3501 - Abell 4000 Abell S1 - Abell S500 Abell S501 - Abell S1000 Abell S1001 - Abell S1174