Absolute Proper Motions of Open Clusters: I. Observational data

TL;DR

This paper presents the determination of mean proper motions and parallaxes for 205 open clusters using Hipparcos data, validating cluster memberships and comparing parallaxes with photometric distances.

Contribution

It provides a comprehensive set of proper motions and parallaxes for open clusters, combining Hipparcos data with ground-based observations to improve cluster membership and distance estimates.

Findings

Good agreement between Hipparcos parallaxes and photometric distances.

Confirmed or rejected Cepheid memberships in clusters.

Identified 630 certain and 100 possible cluster members.

Abstract

Mean proper motions and parallaxes of 205 open clusters were determined from their member stars found in the Hipparcos Catalogue. 360 clusters were searched for possible members, excluding nearby clusters with distances D < 200 pc. Members were selected using ground based information (photometry, radial velocity, proper motion, distance from the cluster centre) and information provided by Hipparcos (proper motion, parallax). Altogether 630 certain and 100 possible members were found. A comparison of the Hipparcos parallaxes with photometric distances of open clusters shows good agreement. The Hipparcos data confirm or reject the membership of several Cepheids in the studied clusters.