Investigations on Proper Motion. XXIII. The Proper Motion of the Cluster H Persei.

On two pairs of plates, taken at the 80-foot focus of the 60-inch reflector, with intervals of 29 and 17 years, 800 stars in the central part of h Persei were measured for proper motion. The probable error of the motions is O'~OOO67 in each co-ordinate. Over a hundred stars were found not to belong to the cluster, in- cluding practically all the field stars brighter than magnitude 15; for the fainter stars it is more difficult to decide about possible membership in the cluster