|
Description
A catalogue of positions and proper motions of 58483 stars (Pul-3) has been constructed at the Pulkovo observatory. The Pul-3 is based on the results of measurements of the photographic plates ((x,y)-data) with galaxies (Deutsch's plan). The observations were made with Pulkovo Normal Astrograph (F=3467mm, D=330mm) during the periods from 1935 till 1960 (the first epoch) and from 1969 till 1986 (the second epoch). The radius of working field was 50 arcmin for all plates. The exposure times were 1 hour. All plates were taken near the meridian. The measurements of the plates were made at the Pulkovo observatory in 1970-s and in 1980-s with ASCORECORD measuring machine. Photographic magnitudes of these stars have been determined at the Pulkovo observatory. The Pulkovo plates contain stars mainly 12-16.5 magnitudes in 146 field in declination zone from -5 to +85 degrees. The maximal density of stars in the Pulkovo plates is 500 stars per square degree. The Tycho-2 catalogue (Cat. <I/259>) has been used as a reference catalogue for astrometric reductions of the photographic plates. The great stars density of the Tycho-2 provides 40-65 reference stars in working field of the Pulkovo plates. Only approximate equatorial coordinates of the optical centers of all plates had been known in initial stage of construction of the Pul-3 catalogue and thus recalculation of ones has been done. A six-parameter plate model has been used for the astrometric reduction of the plates. The residuals of the tangential coordinates of reference stars have been analysed to investigate residual systematic errors. The coma parameters have been determined and coma-dependent systematic errors have been excluded. The magnitude-dependent systematic errors and color-dependent ones were investigated. The most significant corrections for magnitude equation have been obtained for stars brighter than 9 magnitude and fainter than 14 magnitude. The most significant color corrections have been obtained in equatorial zone for declinations of stars. The corrected coordinates of all stars have been determined. On the whole, recalculation of the plates optical centers and taking into account of all revealed systematic errors provide improvement of the accuracy of coordinates of stars on 64mas and 51mas for right ascension and declination correspondingly. The new proper motions have been determined for all stars. The mean position has been calculated at the mean epoch of observations of each star using it proper motion. The mean epoch of the Pul-3 is 1963.25. The internal positional accuracy of the Pul-3 catalogue at the mean epoch of observations is 80mas. The internal accuracy of the proper motions is 5mas/yr. Comparisons of the Pul-3 with Tycho-2 and ARIHIP have been done. The Pul-3 external positional accuracy relative to Tycho-2 is 150mas at the mean epoch of the Pulovo plates. The Pul-3 catalogue successfully represents the Tycho-2 system for more than 50000 stars which are fainter than 12 magnitude in 146 fields. The stars from the Pul-3 catalogue may be used as reference stars for reductions of the positional CCD-observations of the extragalactic radio sources and small bodies of the Solar system. The 40-years difference between Pul-3 observational epoch and modern epoch will allow to determine high precision proper motions of the faint stars of the Pul-3 catalogue (about 2mas/yr-3mas/yr). Proper motions of stars from Pul-3 catalogue may be used for stellar kinematics investigations. There are two data files for user's convenience: - the file pul3.dat represents the Pul-3 catalogue; - the file centers.dat contains the equatorial coordinates of centers of the Pulkovo fields (RA, DE).
|
