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Description
GPM is the newer version of the General Compiled Catalogue of Absolute Proper Motions, derived with respect to galaxies within the plan called Catalogue of Faint Stars (KSZ, Deutch, 1952, Trans. IAU, Vol. 8, 789). The programme was proposed for several observatories of the former Soviet Union, China, Rumania and Spain. There are some resulting individual catalogues of absolute proper motions of stars compiled at five observatories (Kiev, Pulkovo, Moscow, Tashkent and Shanghai). The GPM combines these catalogues and comprises absolute proper motions for 52805 stars from 8 to 15.5mag in 185 fields north of -25 degrees of declination. The size of each region is nearly 1.5 square degrees. The mean standard error of proper motion is 8 mas/yr on average. Detailed information on the construction methodology and input data can be found in (Rybka & Yatsenko, 1997KFNT...13e..70R). In addition to absolute proper motions the GPM contains accurate equatorial coordinates and three-colour B V R photometry for the vast majority of its stars (Rybka 2000KFNT...16e..60R). Additional information was selected from all available sources. Usage of the ACT catalog should provide improved positions (mostly in removing of systematic errors) and improved photometry (because the brightest stars in each GPM region had B and V magnitudes measured by the Tycho experiment on the Hipparcos satellite). The mean accuracies achived, as demonstrated by comparison with above catalogue, are 250 mas for the positions and 0.22mag for B magnitude and 0.26mag for B-V colour. The GPM gives right ascensions and declinations for equinox J2000.0 and epoch copied from available sources. They were only presented to identify the GPM stars with those from other catalogues. The compiled catalogue also presents B magnitudes and B-V colours. They were converted to be close to Johnson system. The Tycho stars were also identified in the GPM catalogue. A search area with a radius of 2 arcseconds was used to search for multiple entries of the same star, which may be appeared in the region overlap areas. The detected entries were then removed from the final catalogue. The procedure decreased the number of stars in the catalogue by about 0.4 %. The adopted catalogue organization includes data in 185 regions sorted according the KSZ region numbers. The data were then sorted nearly in right ascension order within each GPM region. All information needed to associate a point on the sky with region number and provide a more rapid access to that region are given in file region.dat.
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