next previous
Up: Abstract

A&A Supplement Ser., Vol. 124, July 1997, 157-161

Received September 11; accepted November 20, 1996

Absolute proper motions for the calibration of the Hipparcos proper motion system

M. Geffert tex2html_wrap918 - A.R. Klemola tex2html_wrap920 - M. Hiesgen tex2html_wrap922 - J. Schmoll tex2html_wrap924

Send offprint request: M. Geffert

tex2html_wrap926  Sternwarte der Universität Bonn, Auf dem Hügel 71, D-53121 Bonn, Germany
tex2html_wrap928  Lick Observatory, University of California, UCSC, Santa Cruz CA 95064, U.S.A.
tex2html_wrap930  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.gif

keywords: astrometry -- reference system -- stars: kinematics

Copyright by the European Southern Observatory (ESO)