Proper motions of Hipparcos stars in two plate areas.

Abstract

By using the ACT Reference Catalogue as a preliminary reference catalogue, the authors have reduced 31 exposures on 15 plates in areas of two plates taken with the 40 cm refractor at She-Shan Station of Shanghai Astronomical Observatory. By means of the central overlapping technique and the iterative process, the highly precise positions and proper motions of 54 stars, including 16 Hipparcos stars in the two plate areas are obtained. The mean values of the internal standard errors of proper motions in right ascension and declination for the 16 Hipparcos stars are 0.70 mas/yr and 0.59 mas/yr, respectively. The mean values of the internal standard errors of their positions are 10.5 mas and 7.5 mas in right ascension and declination, respectively.