Astrometry and photometry of 7 open clusters

Dias4, Dias6, and four other clusters had UBVRI photometric observations determined for the first time. From the observational UBVRI data we obtained photometric membership probability estimates and, using the proper motions from the UCAC5 catalogue, we also determined the kinematic membership.

From Gaia DR2 astrometric data we determine the stellar membership using proper motions and parallaxes, taking into account the full covariance matrix. For both independent sets of data and membership we apply our non-subjective multidimensional global optimization tool to fit theoretical isochrones to determine the distance, age, reddening, metallicity, and binary fraction of the clusters. The results of the mean proper motions, distances, and ages are in agreement, but the ones obtained from Gaia DR2 data are more precise in both membership selection and estimated parameters.