THE EXAMINATION OF OPTICAL MICROVARIABILITY IN RADIO-QUIET AND RADIO-LOUD QUASI-STELLAR OBJECTS

Preliminary results of a continuing search for significant optical mic rovariations in a selected sample of radio-quiet and radio-loud quasi- stellar objects are reported. Only one object out of nine radio-quiet QSOs observed shows night-to-night variations in brightness. On the co ntrary, all four radio-loud QSOs which were observed show evidence for microvariations. The absence of the microvariations does not provide support for theoretical models utilizing discrete events in accretion disks. Therefore, our results are consistent with models based on shoc ks propagating down relativistic jets as the most likely process respo nsible for producing most of the microvariations observed in the AGNs.