A series of star catalogues covering the whole sky, obtained from measurements of photographs taken with normal astrographs at many observatories between 1891 and 1950 as part of the Carte du Ciel project. It was published in 21 sections, each covering a zone of declination measured from a particular observatory, between 1899 and 1971. The general limiting magnitude is about 11 (photographic), but some observatories included fainter stars. In 1997 the US Naval Observatory published the AC 2000 catalogue, containing 4 621 836 stars measured as part of the original Astrographic Catalogue project but with their positions converted to the same reference frame as the modern Hipparcos Catalogue. A revised version, AC 2000.2, was released in 2001, incorporating photometry for 2.4 million stars from the Tycho-2 catalogue.

http://cdsarc.u-strasbg.fr/viz-bin/Cat?I/275 Detailed description and full catalogue downloadable from the CDS.