We present a proper motion catalogue of 2 670 974 stars, covering the declination zone +11• ≤ δ ≤ +18• . Proper motions were derived from the comparison of the positional M2000 catalogue (systematic observations of the Bordeaux Carte du Ciel Zone with the meridian circle, completed in 2000) with positions derived from the reduction of 512 Carte du Ciel plates of the Bordeaux zone (scanned at the APM Cambridge), the AC2000.2 catalogue, the USNO−A2.0 catalogue and the unpublished Yellow Sky (YS3) USNO catalogue. The catalogue has a limiting magnitude V M = 16.2 (Bordeaux CCD meridian circle magnitude) and is complete down to V M = 15.4. Depending on magnitude, the positional precision at mean epoch ranges from 50 to 70 mas and the precision of proper motions varies from 1.5 mas/yr to 6 mas/yr. Meridian V M magnitudes are provided for all objects together with additional photometry from the 2MASS catalogue when available (99.5% of objects). Positions and proper motions are on the ICRS (International Celestial Reference System). Systematic offsets in 2MASS positions and in UCAC2 proper motions were revealed from comparisons with PM2000.
Context. This work is part of a program of proper motion measurements in the Bordeaux Carte du Ciel zone. Aims. We present the CdC2000 catalogue issued from the reduction of the complete Bordeaux Carte du Ciel zone observed at the begining of last century with the Bordeaux astrograph. Methods. Plates have been individually reduced using the TYCHO-2 Catalogue as the astrometric reference.Results. This catalogue is a positional catalogue of 344 781 stars covering the declination zone +11• ≤ δ ≤ +18• . The average epoch of positions is 1914.7. The data are from the 512 Carte du Ciel plates archived at the Bordeaux Observatory and scanned with the APM Cambridge automatic measuring machine. Astrometric standard errors are about 0.10 to 0.12 on positions and 0.6 mag on photographic magnitudes. Conclusions. A detailed study of errors and a comparison of various reduction methods are presented in order to take into account the significant propagated errors from the reference catalogue. The CdC2000 provides positions at the epoch of the plates for 50 682 TYCHO-2 stars. The associated positions are proved to be √ 2 more precise than the positions given by the TYCHO-2 catalogue at the epoch of the plates (0.11 instead of 0.15 ). This work is part of a program of proper motion measurements in the Bordeaux Carte du Ciel zone.
Context. First Epoch astrometric and radiometric information of a survey in the optical along the Galactic fourth quadrant is archived for further analysis in the time-domain. Aims. A photographic survey of 1.9 × 10 6 stars down to B-magnitude 14 ± 0.5 along the galactic meridian l = (330 ± 5)• , −64• ≤ b ≤ −7• and along the galactic equator 272• , is provided from century old astrographic plates of Sydney Observatory. Stellar candidates to investigate the Galaxy disk kinematics up to a distance of 1 kpc from the Sun are tentatively selected. Methods. The early data are combined with late epoch observations into a set of 4.8 × 10 5 stars with significant proper motion µ ≥ 0.005 yr −1 and approximate color B − V. The selection effects and the kinematical bias on the stellar system are investigated. F-G stellar candidates with a mean transverse velocity dispersion of 45 km s −1 are suggested. Results. The spin rate of 1 2• pc −1 of the velocity ellipsoid along its long axis is observed over half a thickness of 25 pc of the galactic disk for stars at an estimated distance D ≤ 300 pc from the Sun. Conclusions. A catalogue of 4.8 × 10 5 stars is provided for further investigation of the galactic disk heating by transient spiral wave or by GMC encounter.Key words. surveys -stars: kinematics Retrospective of early astrographic surveysFirst epoch observations used in the proper motion (p.m.) determination of faint stars observed in the Tycho-2 catalogue are based on short exposure plates observed for the Astrographic Catalog (AC) at the beginning of the 20th century over a field of view of 2• × 2 • for each of the 4 × 10 4 AC plates at a scale of 1 mm −1 , proving that photographic observations from the past were indeed durable even at the time of space astrometry (Urban et al. 1998). In order to check the quality of the old plates with a fast measuring machine like APM, used for instance to scan large Schmidt plates (Evans 1992), a set of 104 short exposure plates dating from the late 19th century was selected from the plate vault of Sydney Observatory, archived at Macquarie University.The double exposure technique used in the astrophotographic survey is shown in Fig. 1: stars are identified in the image inventory of a plate scanned with APM by the combination of double images. Along with the x, y plate mean coordinates (in mm) and their errors ∆x, ∆y (in microns), an indication of short term magnitude variability ∆m, is also computed for each star: this information is not available from the AC measurements but is usable to search for flare stars (Fresneau et al. 2001). The (ξ, η) plate coordinates (in arcmin) for the Tycho-2 stars The quality of the best linear unbiased estimation of the set of 12 plate constants (A, B, C, D, E, F and A , B , C , D , E , F ) after the weighted least squares fit is measured by the rms error σ T between the computed and observed equatorial coordinates of the set of Tycho-2 stars (a couple of hundreds per 2 • × 2 • field of view). The same stars are also used to derive a calibrat...
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