(The Third US Naval Observatory CCD Astrograph Catalog) was released on
a double sided DVD containing 8Gb of binary files during September 2009.
Herbert Raab added support for UCAC-3 to Astrometrica in version
220.127.116.114 in January 2010 and was used at Great Shefford from
7th January 2010 until February 2013 when support for UCAC-4 was made
available. A number of improvements were made to the UCAC-2
here) including extending the coverage to the entire sky.
(The Second US Naval Observatory CCD Astrograph Catalog) was released on
three CDs by the USNO at the end of July 2003 and the CDs were received
at Great Shefford a week or so later. By 19 Aug 2003 Herbert Raab had
issued Astrometrica version 18.104.22.1685 with support for the new
UCAC2 did not cover the entire sky, but extended from the south pole
to about +45° declination. See
a plot of the coverage from the USNO.
UCAC2 was used at Great Shefford for all reductions within its
coverage. Outside of this area USNO B1.0 was used (see below).
Magnitudes derived from measures using UCAC2 have been found to be
about 0.5 mags fainter than the equivalent using the USNO A2 or B1
USNO B1.0 was used at Great Shefford from 2003 March until 2003
August for all reductions reported
to the MPC wherever possible. This catalogue is currently only available
by downloading small parts over the web from http://www.nofs.navy.mil/data/FchPix/
. Astrometrica can use this catalogue directly.
USNO A2.0 contains 526 million stars and is used for telescope position
synchronisation by Pinpoint from within Maxim DL/CCD during observing
runs. It is obsolete for astrometric purposes as it does not include
stellar proper motion information but at 5.9Gb is easily held on a hard
disk and has good all-sky coverage.