This is basically a reversal request for #681654 [1].
For the use of the Tycho-2 catalog [2] with the "astrometry.net" program
(currently in NEW) [3], I contacted the author of the catalog, and after
some iterations, I got the confirmation that the catalog may be
distributed under a BSD-2-Clause license -- see the attached E-Mail.

Since this makes the Tycho-2 catalog DFSG-free, I would propose to move
it back to Debian/main.

If you can provide me with the rule how to create the kstars catalog
from the original one, I would also happily create the
kstars-data-extra-tycho2 binary package within my package.

Best regards

Ole

[1] http://bugs.debian.org/681654
[2] http://bugs.debian.org/795933 (ITP)
[3] http://bugs.debian.org/793461 (ITP)