Proper motions of 59 766 stars absolutized using galaxies in 149 sky fields (PUL2)

The PUL2 catalog has been photographically compiled in Pulkovo according to Deutch's plan. The catalog contains the mean coordinates of stars in the ICRS system at epoch J2000.0 and their original absolute proper motions. The photographic observations were performed with a normal astrograph. The first and second epochs of the photographic plates are 1937–1965 and 1969–1986, respectively. The PUL2 fields uniformly cover the northern sky. The mean difference between the epochs is 24 years. At least three pairs of plates are available for each field. There are one-hour and five-minute exposures on all plates. One pair of plates was taken with a diffraction grating. Only bright reference stars were measured on the pairs of plates with a grating. Based on a reduction model with six constants and using faint (\(15\mathop m\limits_. 2\)) reference stars, we determined the relative proper motions of the stars. We used ～700 galaxies for absolutization. The mean errors in the relative proper motions of the PUL2 stars are 5.5 mas yr^?1 (milliarcseconds per year) in μ_α cos δ and 5.9 mas yr^?1 in μ_δ. When using galaxies, the mean absolutization error is 7.9 mas yr^?1 in both coordinates. By comparing the PUL2 and HIPPARCOS catalogs, we determined the components of the residual rotation vector ω for HIPPARCOS relative to the extragalactic (equatorial) coordinate system: ω_x,y,z=(?0.98, ?0.03, ?1.66)±(0.47, 0.38, 0.42) mas yr^?1. The mean error of one absolute proper motion of a bright PUL2 star in external convergence is 9 mas yr^?1 in both coordinates.