This subdirectory contains the Abell Catalogue of Rich Clusters of Galaxies.
See the file abell.txt for details about the catalogue contents.

The files with the extension ".zip" are PKZIP archives of MS-DOS format
versions of the data and notes.  Those with the extension ".gz" are gzipped
UNIX versions of the same data and notes.  Take whichever is easiest for
you to handle.  Aside from the compression technique, and the line endings,
the two sets of files/data are identical.

N.B. Heinz Andernach, University of Guanajuato, has found that m_1 
is missing for two clusters.  The correct values are:

  Abell 3163:  17.0
  Abell S286:  18.0

He has also noted an incorrect Bautz-Morgan class for Abell 2503;
the correct class is "I-II:".

These corrections all appear in the tables available here. 
hgcjr, 26 Mar 07