Re: Ensemble analysis: "new variables"

[Stupendous Man <richmond@a188-l009.rit.edu>]

  Let me second Arne's note that one must be careful not to
pick saturated stars as input to an ensemble average.  
Andrew, if you have already matched up the TASS stars
to the Tycho catalog, let me recommend that you simply
choose stars within a "sweet spot" of magnitude: for example,
stars with 9 < V < 10, and 9 < I < 10.  Your numbers will
probably be different, but I hope you see what I mean.

  In fact, you can pre-process the Tycho catalog in the area
of a particular image, and pick out the good ensemble stars in advance.
You might even make up a separate catalog of "good" Tycho stars
for this use...

                                      Michael