A comprehensive study of 94 open clusters based on the data from IPHAS, GAIA DR2, and other sky surveys. L.N. Yalyalieva, A.A. Chemel, E.V. Glushkova, A.K. Dambis, and A.D. Klinichev Abstract: We determine the color excesses, photometric distances, and astrometric parallaxes and proper motions for 94 open clusters in the northern part of the Milky Way. We estimate the color excesses and photometric distances based on the data from IPHAS photometric survey of the northern Galactic plane using individual total-to-selective extinction ratios R_r=A_r/E(r-i) for each cluster computed via the color-difference method based on photometric data from several large-scale sky surveys (IPHAS, 2MASS, WISE, and Pan-STARRS). The inferred R_r values vary significantly from cluster to cluster spanning the R_r~=3.1--5.2 interval with a mean and standard deviation equal to ~=3.99 and sigma(R_r)=0.34, respectively. We identify cluster members using (1) absolute proper motions determined from individual-epoch positions of stars retrieved from several major sky surveys (IPHAS, 2MASS, URAT1, ALLWISE, UCAC5, Gaia DR1, USNO-B1.0) reduced to a common frame defined by UCAC5 catalog and (2) absolute proper motions provided in Gaia DR2 catalog, and computed the average Gaia DR2 trigonometric parallaxes and proper motions of the bona fide members in each cluster. The mean formal error of the inferred astrometric parallaxes of clusters is of about 7~microarcseconds, however, a comparison of astrometric and photometric parallaxes of our cluster sample implies that Gaia DR2 parallaxes are, on the average, systematically underestimated by 45+/-9~microarcseconds. This result agrees well with other published estimates. At the same time, we find our photometric distance scale to be correct within the quoted errors (the inferred correction factor is equal to unity to within a standard error of 0.025). Description: Parameters of 94 Milky Way open clusters calculated using photometric data from IPHAS and astrometric data from GAIA DR2. File Summary: ------------------------------------------------------------------------------------------------------------- FileName Lrecl Records Explanations ------------------------------------------------------------------------------------------------------------- ReadMe 94 . This file catalog.txt 111 110 Catalog of OC's parameters ------------------------------------------------------------------------------------------------------------- Byte-by-byte Description of file: OpenClusters.txt ------------------------------------------------------------------------------------------------------------- Bytes Format Units Label Explanations ------------------------------------------------------------------------------------------------------------- 1 - 13 A8 --- Name Name of the cluster 14 - 18 F4.0 pc D Photometric distance to the cluster 19 - 22 F3.0 pc e_D Standard error of the distance 23 - 28 F5.3 mas plx Photometric parallax of the cluster 29 - 34 F5.3 mas e_plx Standard error of the parallax 35 - 40 F5.3 mas plx_gaia Trigonometric parallax of the cluster from GAIA DR2 41 - 46 F5.3 mas e_plx_gaia Standard error of the parallax from GAIA DR2 47 - 50 F3.1 --- lg(t) Logarithm of the cluster age 51 - 56 F5.3 --- Rr Extinction-law parameter Rr 57 - 62 F5.3 --- e_Rr Standard error of the extinction-law parameter 63 - 68 F5.3 mag Ar Total extinction in the r-band 69 - 73 F5.3 mag e_Ar Standard error of the total extinction 74 - 80 F5.3 mag alpha Exponent alpha 81 - 86 F5.3 mag e_alpha Standard error of the exponent alpha 87 - 93 F6.3 mas/year pmra Average proper-motion component of the cluster along right ascension 94 - 99 F5.3 mas/year e_pmra Standard error of pmra 100 -106 F6.3 mas/year pmde Average proper motion component of the cluster along declination 107 -111 F5.3 mas/year e_pmde Standard error of pmde -----------------------------------------------------------------------------------