Note: The GSC-ACT (or GSC1.3) is a recalibration of the GSC1.1, the catalogue constructed to support the operational need of the Hubble Space Telescope, with the ACT, the combination of the Astrographic Catalogue and the Tycho catalogue derived from the Hipparcos mission; see http://www.projectpluto.com/gsc_act.htm for more details about this recalibration.
Note: The current version includes only the North (POSS-I plates)
Note: 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:
(original column names in green) (1811709771 rows)
Note: SDSS is also available from http://www.sdss.org/
Note: SDSS is also available from http://www.sdss3.org/dr9/
Note: (see also the postcard server)
Note: The recommended designation for the 7C sources is made from the full B1950 position with template 7C HHMMSS.s+DDMMSS
Note: The column FIRST provides a link to the FIRST cutout image server (see also the original FIRST search engine)
Note: The ``short'' version of the catalogue can be retrieved by a selecting *+* in the SEQflags column