Hipparcos stars proper motions

The proper motions have been recently used as part of the Bonn program for the extragalactic link of the Hipparcos proper motion system. We describe methods which have led to the absolute proper motions of the major part of the Bonn fields for the link.

For six fields the extragalactic calibration was achieved using the bright quasar in the centre of the field. In addition, data of three fields of globular clusters were included. For these fields the link to an extragalactic reference system was performed by stars, whose absolute proper motions with respect to galaxies were determined on plates of the Lick astrograph.