BL LACERTAE: LONG-TERM, INTRADAY AND INTRAHOUR VARIABILITY

Abstract

We present preliminary results of the optical observations of BL Lacertae during the period June-November 2001 carried out using an ST-6 charge-coupled device camera attached to the Newtonian focus of the 70 cm meniscus telescope of the Abastumani Observatory. The aim of these observations is to study the long-term variability, intranight variability and intrahour variability of BL Lacertae. The overall long-term variation in the R band has a magnitude of 1.80 (rms, 0.03). We also demonstrated that the typical average amplitudes of the intraday variability and the intrahour variability in the R band are of magnitudes 0.30 ± 0.02 and 0.10 ± 0.01 respectively. The maximum amplitudes of both types of variation are of magnitude 0.40 ± 0.02.