Analysis of USNO-B1 proper motions of stars in open-cluster fields
Abstract
USNO-B1 proper motions for stars in the fields of NGC 457 and χ and h Per open clusters are analyzed and compared to the the proper motions based on plate material taken with normal astrographs. USNO-B1 proper motions in central regions of clusters are found to have large errors due mostly to numerous misidentifications in crowded fields. At the same time, USNO-B1 proper motions for the rest of cluster stars proved to compare fairly well to those inferred in classical astrometric studies. Standard deviations of the proper-motion differences between USNO-B1 and cluster proper-motion studies are found to be on the order of 3.4–4.2 mas yr−1.