Optical multi-color monitoring of OJ 287 from 2006 to 2012

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2017,（8）
• 页码范围: 133-144
• 页数: 12页
• 语种: 英文
• DOI: 10.1088/1674-4527/17/8/82

摘要

We present our optical multi-color monitoring of the BL Lac object OJ 287 from January 2006 to December 2012 in the V,R and I bands.A relatively active state in OJ 287 has been found over all monitored epochs,among which the variations of average magnitude in V/R/I bands were measured with △V =1.956 mag,△R =2.067 mag and △I =2.115 mag,respectively.No reliable intraday variability is detected,but possible variability is detected on 16 nights.Their relative variation amplitudes fall into the range between 1％ and 8％,with the majority between 2％ and 4％.No time lags have been detected,but strong correlations exist among light curves in the three wavebands.The bluer-when-brighter trend is dominant over intraday timescales,which supports the shock-in-jet model.When combining with additional V/R band data obtained from SMARTS and the Steward Observatory,we also find a bluer-when-brighter trend over a long-term timescale.Some possible periods of 513,176,36,30,26,17 and 14 d are found in all time-series data sets from 2006 to 2017.Possible explanations about these periods are given.