A catalogue of 2712 rich clusters of galaxies published in 1958 by the American astronomer George Ogden Abell (1927–83) from inspection of the Palomar Observatory Sky Survey photographs. The catalogue had well-defined criteria for selection of the clusters (see Abell Cluster). A later extension to the southern sky (published 1989) was based on photographs taken with the United Kingdom Schmidt Telescope in Australia.
http://cdsarc.u-strasbg.fr/viz-bin/Cat?VII/110A Detailed description and full catalogue downloadable from the CDS.