Se. Urban et Te. Corbin, NEW REDUCTIONS OF THE ASTROGRAPHIC CATALOG - CONVENTIONAL PLATE ADJUSTMENT OF THE CAPE-ZONE, Astronomy and astrophysics, 305(3), 1996, pp. 989-998
The U. S. Naval Observatory is in the process of making new reductions
of the Astrographic Catalogue using a modern reference star system, t
he ACRS, created specifically for that purpose. The application of tha
t system to the plates of the Cape Zone is discussed as well as the so
ftware that has been developed to make the reductions. An analysis of
scale, rotation, tilt, coma, magnitude equation, radial distortion and
distortions introduced by the use of reseaux in the Carte du Ciel pro
gram is made for each plate. The result is a catalog of 544 629 stars
from plates taken at the Cape Observatory between 1897 and 1911 on the
system of FK5 J2000. The average standard deviations of an individual
plate image after reduction are 0 ''.31 in right ascension and 0 ''.2
8 in declination. Thus the positions of the Cape Zone, and of the othe
r zones subsequently to be reduced, can be combined with modern astrom
etric catalogs to give accurate proper motions for large numbers of st
ars.