A&A Supplement Ser., Vol. 124, July 1997, 157-161
Received September 11; accepted November 20, 1996
M. Geffert
- A.R. Klemola
- M. Hiesgen
- J. Schmoll
Send offprint request: M. Geffert
Sternwarte der Universität Bonn, Auf dem Hügel 71,
D-53121 Bonn, Germany
Lick Observatory, University of California, UCSC,
Santa Cruz CA 95064, U.S.A.
Astronomisches Institut der Universität Münster,
Wilhelm-Klemm-Str. 10
D-48149 Münster, Germany
Absolute proper motions of 48 Hipparcos stars in nine fields
distributed over the northern hemisphere
are presented. 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. In addition, we used for the link
in one field plates from the ESO Schmidt telescope
in combination with measurements from glass copies of the
Palomar Sky Survey.
The accuracy of a single proper motion is of the order
of 2 to 3 mas/a for each coordinate.
keywords: astrometry -- reference system -- stars: kinematics