CCD Photometry and Optical Variability of Gamma-Ray-loud BL Lacertae Object OJ 287 in a Low, Fainter State

摘要

We present optical photometry (V, R, and I) of the BL Lac object OJ 287 (0851+203, z = 0.306), which was observed in a low, fainter state with the 1 m telescope at Yunnan Astronomical Observatory. Our results show significant short-term variability in the R band over 31 minutes. We find a strong correlation between the V - R color index and the magnitude in the R band. Our CCD photometry of OJ 287 is in good agreement with the prediction of Sillanp?? and coworkers of an optical variability period of about 11.6 yr.