The catalogue of positions of optically bright extragalactic radio
  sources OBRS-1
  It is expected that the European Space Agency mission Gaia will make possible
to determine coordinates in the optical domain of more than 500000 quasars. In
2006, a radio astrometry project was launched with the overall goal to make
comparison of coordinate systems derived from future space-born astrometry
instruments with the coordinate system constructed from analysis of the global
very long baseline interferometry (VLBI) more robust. Investigation of their
rotation, zonal errors, and the non-alignment of the radio and optical
positions caused by both radio and optical structures are important for
validation of both techniques. In order to support these studies, the
densification of the list of compact extragalactic objects that are bright in
both radio and optical ranges is desirable. A set of 105 objects from the list
of 398 compact extragalactic radio sources with declination > -10 deg was
observed with the VLBA+EVN with the primary goal of producing their images with
milliarcsecond resolution. These sources are brighter than 18 magnitude at V
band, and they were previously detected at the European VLBI network. In this
paper coordinates of observed sources have been derived with milliarcsecond
accuracies from analysis of these VLBI observations following the method of
absolute astrometry. The catalogue of positions of 105 target sources is
presented. The accuracies of sources coordinates are in the range of 0.3 to 7
mas, with the median 1.1 mas.
