A&A Supplement series, Vol. 129, May I 1998, 569-575
Received February 2, 1996; accepted September 19, 1997
G.B. Jia - X.F. Cen - H.Y. Ma - J.C. Wang
Send offprint request: G.B. Jia
Yunnan Observatory, Academia Sinica, P.O. Box 110, Kunming, Yunnan, P.R. China
Results of BVRI CCD photometric monitoring and fast photometry in the I band for the blazar OJ 287 in 1994-1995 are presented. The predicted outburst of the blazar had been observed, the maximum appeared in 1994 November, after that, the luminosity decreased by 1.6 mag for about three months and dropped to near the level in 1994 April. Rapid variations with timescales of minutes, hours and one day were observed in our observations, with small amplitude. The amplitude of the most rapid variations (minutes) is in the range of . The results of the statistical analysis of the fast photometry data are as follows. In five nights out of six rapid variability appeared in the sampling interval, which ranged from 3.4 minutes to 6.5 minutes, with a rms amplitude of flux variations of .
The rapid variability can be explained by the model of shocks within turbulent jet or of vortices and magnetic flux tubes on accretion disk.
keywords: BL Lacertae objects: individual: OJ 287 -- galaxies: active