[Comm2011] New photometric standard star catalog

[Ewout M. Helmich]

Hi,

I've committed a new version (v12) of the standard star catalog. This 
will automatically be used from now on. The difference is in the Sloan 
stars. Compared to v11, DR5 stars have been replaced by DR7, and the 
size of the extracted areas around SA field centers was increased to 
2.5x2.5 degrees from 1.1x1.1 degrees. For SA112 I've limited the size to 
1.7x1.7 degrees because its a dense field and the number of returned 
sources appears to be capped by the Sloan database.

Because of the large field sizes the new catalog is 56MB (up from 33MB). 
For performance reasons, we may decide in the future to remove SA fields 
we don't use, or decrease their sizes.

Regards,
Ewout