M2000: An astrometric catalog in the Bordeaux Carte du Ciel zone +11degr <= delta <= +18degr
Ducourant, C.; Soubiran, C.; Le Campion, J. -F.; Colin, J.; Viateau, B.; Rapaport, M.; Daigne, G.; Périé, J. -P.; Bosq, F.; Desbats, J. -M.; Mazurier, J. -M.; Montignac, G.; Ralite, N.; Réquième, Y.
France
Abstract
During four years, systematic observations have been conducted in drift scan mode with the Bordeaux automated meridian circle in the declination band +11degr <= delta <= +18degr . The resulting astrometric catalog includes about 2.3x 106 stars down to the magnitude limit VM=16.3. Nearly all stars (96%) have been observed at least 6 times, the catalog being complete down to VM=15.4. The median internal standard error in position is ~ 35 mas in the magnitude range 11 < VM <15, which degrades to ~ 50 mas when the faintest stars are considered. M2000 also provides one band photometry with a median internal standard error of ~ 0.04 mag. Comparisons with the Hipparcos and bright part of Tycho-2 catalogs have enabled us to estimate external errors in position to be lower than 40 mas. In this zone and at epoch 1998, the faint part of Tycho-2 is found to have an accuracy of 116 mas in alpha instead of 82 mas deduced from the model-based standard errors given in the catalog. The catalog is distributed on CD-ROM and through the CDS (http://cdsweb.u-strasbg.fr/Cats.html). Further information is given on the website http://www.observ.u-bordeaux.fr/~soubiran/m2000.htm