Note: Note that the J2000 coordinates are not part of the original catalogue, they were computed from dRAs and dDEs, or from the (rho,theta); their accuracy can be low.
Note: More recent versions available: UCAC3 (I/315) and UCAC4 (I/322); see also the UCAC home page at http://ad.usno.navy.mil/ucac/
The Naval Observatory Merged Astrometric Dataset (NOMAD) contains
astrometric and photometric data for over 1 billion stars derived from
the Hipparcos (I/239), Tycho-2 (I/259), UCAC2 (I/289), and USNO-B1.0
(I/284) catalogs for astrometry and optical photometry, supplemented
by 2MASS (II/246) near-infrared photometry.
An efficient remote query program findnomad1 is
available in the cdsclient
package, for Unix/Linux platforms
Note: This version of the
has no proper motions, but the limits on brightness which existed on
GSC2.2 (F<18.5, Bj<19.5) were removed.
Note: see the UCAC4 document, and the
the fix for high proper motion stars.
The UCAC home page is available at
Please acknowledge the usage
of the UCAC4
Note: Zone -40/+50deg
Note: Many errors detected in the positions given in the catalogue, especially in the sign of the declination in the zones -1°<δ<+1°
Note: The column expnum provides an access to details on the exposures, and a link to the Preview and Retrieval System via the CADC
Note: Details of surveyed literature