Optical positions of compact extragalactic radio sources with respect to the Hipparcos Catalogue

Optical positions relative to the Hipparcos Catalogue, and therefore within the International Celestial Reference System (ICRS), have been obtained for the optical counterparts of 25 compact extragalactic radio sources (CERS) south of +10 .M ost of these sources are being monitored as Benchmark objects for the establishment of a unied extragalactic radio/optical ref- erence frame. Precision levels as good as 0.1 00 in both co- ordinates were achieved. A comparison with VLBI radio positions available for these sources is presented. A nding chart is given for the optical counterpart of Q 1937 101. To a limiting magnitude of B 20:5, no optical counter- part was found for the source 1148-671.