7.A. WCS: MSCgetcatalog.

In order to apply a WCS to the images, we need to first generate a catalog of known astrometric positions of the field. This can be done using 'mscgetcat'. Generally the NOAO:USNO-A2 catalog is used, though other options exist.

 
PACKAGE = mscred
   TASK = mscgetcatalog

input   =        obj507p.fits  List of Mosaic files
output  =         M31.F9.usno  Output file of sources
(magmin =      	           0.) Minimum magnitude
(magmax =      	          40.) Maximum magnitude
(catalog=        NOAO:USNO-A2) Catalog
(rmin   =          	  21.) Minimum radius (arcmin)
(mode   =                  ql)

Note that you can do all of this from mscmatch if you wish....