A Finding List for Delta_mu Binaries derived from a Comparison of HIPPARCOS Proper Motions with Long-term Averaged Data

Abstract

The comparison of quasi-instantaneously measured HIPPARCOS proper motions with long-term averaged proper motions, derived from ground-based data, allows the identification of many stellar objects as Delta_mu binaries (Wielen et al., 1999, A&A 346, 675). We have used this method to find Delta_mu binaries among the fundamental stars, among the GC stars, and among the Tycho-2 stars. A finding list for about 4000 Delta_mu binaries is given under the URL http://www.ari.uni-heidelberg.de/dmubin in a machine-readable format. This information on the probable duplicity of the listed objects can be used for planning specific observing programs, for improving our knowledge of binary statistics, or for avoiding the use of these binaries in some astrophysical calibrations or as astrometric reference stars.