Astrometry with "Carte du Ciel" plates, San Fernando zone. II. CdC-SF: a
  precise proper motion catalogue
  The historic plates of the "Carte du Ciel", an international cooperative
project launched in 1887, offer valuable first-epoch material for the
determination of absolute proper motions. We present the CdC-SF, an astrometric
catalogue of positions and proper motions derived from the "Carte du Ciel"
plates of the San Fernando zone, photographic material with a mean epoch of
1901.4 and a limiting magnitude of V~16, covering the declination range of
-10deg < declination < -2deg. Digitization has been made using a conventional
flatbed scanner. Special techniques have been developed to handle the
combination of plate material and the large distortion introduced by the
scanner. The equatorial coordinates are on the ICRS defined by Tycho-2, and
proper motions are derived using UCAC2 as second-epoch positions. The result is
a catalogue with positions and proper motions for 560000 stars, covering 1080
degrees squared. The mean positional uncertainty is 0.20" (0.12" for
well-measured stars) and the proper-motion uncertainty is 2.0 mas/yr (1.2
mas/yr for well-measured stars). The proper motion catalogue CdC-SF is
effectively a deeper extension of Hipparcos, in terms of proper motions, to a
magnitude of 15.
