1994-1996 Optical Outbursts of the BL Lac Object OJ 287

摘要

VRI bands CCD photometric observations of the BL Lac object OJ 287 have been carried out during the period from 1994 October to 1196 May, with a mean interval of about a week. OJ 287 underwent two major outbursts during our observations. The first peak (V = 14.0 mag) occurred in the first half of 1994 November and faded out to 16.5 mag within 150 days. The second peak (V = 14.0 mag) was observed in the second half of 1995 December. The latter peak continued at nearly the same brightness until 1996 May. Such a long lasting outburst has never been reported for OJ 287. Color indices (V - R and V - I) remained nearly constant during the interval.