A&A Supplement series, Vol. 127, January II 1998, 145-152
Received February 13; accepted April 25, 1997
N. Bade 
- D. Engels
- W. Voges 
- V. Beckmann
- Th. Boller
- L. Cordis
- M. Dahlem 
- J. Englhauser
- K. Molthagen
- P. Nass 
- J. Studt
- D. Reimers
Send offprint request: N. Bade; e-mail: nbade@hs.uni-hamburg.de
Hamburger Sternwarte, Gojenbergsweg 112,
D-21029 Hamburg, Germany
Max-Planck-Institut für extraterrestrische Physik,
D-85740 Garching, Germany
ESTEC, Astrophysics Division, Postbus 299,
NL-2200 AG Noordwijk, The Netherlands
We present the Hamburg/RASS Catalogue of optical identifications (HRC).
The catalogue contains optical information about objects inside the error
circles of ROSAT All-Sky Survey (RASS) sources. The information was gathered
from objective prism and direct
plates taken by the Hamburg Quasar Survey (HQS). The plates enable an
effective selection of several X-ray emitting classes of objects,
as there are
galaxies, AGN, QSOs, galaxy clusters and several types of galactic stars,
in particular M dwarfs, hot white dwarfs and cataclysmic variables.
In the current state (November 1996) the HRC contains
information about 3847 X-ray positions and covers about 8480deg2 of the
high galactic latitude (
) northern sky.
For 
of the X-ray sources a plausible optical counterpart is given. The
counterparts of the remaining sources are probably faint ( B > 18.5)
AGN and galaxy clusters.
The HRC is available electronically together with
finding charts taken from the digitized direct HQS plates.
keywords: X-ray sources: general -- galaxies -- stars