VLBI and Compact Radio Sources

I.A.U. symposium No. 110 on VLBI and Compact Radio Sources was held in Bologna, Italy from June 27 to July 1, 1983. 166 participants from 19 countries were registered and 106 invited and contributed papers were registered. The scientific presentations and discussion concentrated on VLBI observation and interpretation of galactic and extragalactic radio sour- ces, including topics as diverse as quasars and galactic nuclei, inter- stellar masers, pulsars, and astrometry. Geodetic applications and tech- nical development were treated only briefly, as these topics have been the subject of other recent international symposia. Since the first VLBI observations in 1967, sensitivity, resolution, and image quality have improved dramatically. Radio maps shown at the symposium were of comparable quality to conventional synthesis maps be- ing made at the time of the first VLBI experiments 15 years ago, but with a resolution more than a factor of 1000 better. We wanted to accommodate the large number of contributed papers in this rapidly developing field, but there was inadequate time for normal oral presentations and discussion. We therefore asked that all contrib- uted papers be put on display for at least 24 hours prior to a brief oral summary. A question and discussion period followed groups of oral pres- entations on the same or similar topic. In this way the opportunity for interactive discussion, not available in conventional poster displays, was preserved.