UrHip Proper Motion Catalog

The goal is to obtain a significant improvement on the proper motion accuracy of single stars in the northern hemisphere, and to identify new astrometric binaries perturbed by orbital motion. For binaries and multiple systems, the longer baseline of Tycho2 (~100yr) makes it more reliable despite its larger formal uncertainties.

The resulting proper motions obtained for 67340 stars have a consequent gain in accuracy by a factor of ~3 compared to Hipparcos. Comparison between UrHip and Hipparcos shows that they are reasonably close, but also reveals stars with large discrepant proper motions, a fraction of which are potential binary candidates.