The fourth U.S. Naval Observatory CCD Astrograph Catalog (UCAC4)
Short Name:
ucac4 scs
Date:
23 Mar 2022 13:13:16
Publisher:
The GAVO DC team
Description:
UCAC4 is a compiled, all-sky star catalog covering mainly the 8 to 16
magnitude range in a single bandpass between V and R.
Positional errors are about 15 to 20 mas for stars in the 10 to 14 mag
range. Proper motions have been derived for most of the about 113
million stars utilizing about 140 other star catalogs with significant
epoch difference to the UCAC CCD observations. These data are
supplemented by 2MASS photometric data for about 110 million stars and
5-band (B,V,g,r,i) photometry from the APASS (AAVSO Photometric
All-Sky Survey) for over 50 million stars. UCAC4 also contains error
estimates and various flags. All bright stars not observed with
the astrograph have been added to UCAC4 from a set of Hipparcos and
Tycho-2 stars. Thus UCAC4 should be complete from the brightest stars
to about R=16, with the source of data indicated in flags.
