| UCAC 2
(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 4.3.0.325 with support for the new
catalogue. Currently UCAC2 does not cover the entire sky, but extends from the south pole
to about +45° declination. See here
a plot of the coverage from the USNO. The final sky observations were
completed in May 2004 and the final part of the catalogue (to +90° dec) is expected
to be released during 2006.
UCAC2 is the most accurate general astrometric
catalogue available at the moment, with positional errors better than
0.1" and is used at Great Shefford for all reductions within it's
coverage. Outside of this area USNO B1.0 is 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
catalogues.
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. It is significantly more
accurate than...
USNO SA2.0 is used on occasion when fast preliminary reductions are
required (at about 650Mb this catalogue fits easily on a hard drive). Normally
positions would be re-reduced using UCAC2 or USNO B1.0 before reporting.
The Hubble telescope GSC 1.1 is used for telescope position
synchronisation by Pinpoint from within Maxim DL/CCD during observing
runs. |
