SHORT-TERM OPTICAL VARIABILITY IN BROAD ABSORPTION-LINE QSOS

We present the first results from a pilot program to monitor the short -term optical variability in broad absorption line system QSOs. Intran ight optical variations of similar to 5% were detected on timescales o f similar to 1 hr in QSOs 0846+156 and 0856+172. Further, the mean mag nitude level decreased in the two objects by similar to 0.05 and simil ar to 0.15 mag, respectively, during the period of our observations. T he observed light curves are quite similar to those previously seen in the flat-spectrum radio-loud sources, especially the BL Lacertae obje cts, and can provide important constraints for the origin of microvari ability and also a possible evolutionary link between the radio-loud a nd the radio-quiet QSOs.