Tech Note 105: Version 2 of the Mark IV "patches" catalog

[Tass Mailing List <tass@mail.alembic.net>]

Date: Wed, 30 May 2007 12:57:50 -0400
From: Michael Richmond <richmond@stupendous.cis.rit.edu>
To: tass@tass-survey.org
Cc: droege@fastmail.fm, mwrsps@rit.edu
Subject: Tech Note 105: Version 2 of the Mark IV "patches" catalog


  Several months ago, Siegfried Roeser and colleagues called my
attention to a systematic error in the photometry of the
Mark IV "patches" catalog.  The size of the error ranged from at most
+/- 0.10 mag near the southern edge of the survey area to +/- 0.02 mag
near its middle.  The error was caused by the method we used to
flatfield the data.

  I've used hints from Siegfried to characterize and remove the
errors, as well as I can.  You can find a detailed report on the
errors in Tech Note 105

      http://stupendous.rit.edu/tass/technotes/tn0105.html

  I have created a Version 2 of the "patches" catalog, which is
identical to the original except for corrections made to the
mean "Vmag" and mean "Imag" columns.  This new version of the
catalog should replace the original.  It can be found on my
"patches catalog" web site

      http://spiff.rit.edu/tass/patches/

  I will contact the people at SIMBAD to see if they will replace
the original patches catalog stored there with this version 2.


                       Michael Richmond