  Context. The blazar OJ 287 has been proposed as a binary black hole system
based on its periodic optical outburst. Among blazars with parsec scale jets,
the black hole binary systems are very rare and hence this source is very
interesting to study. Aims. The BL Lac OJ 287 is an interesting object for
multi-wavelength study due to its periodic outbursts. We have analyzed the
optical, X-ray, and gamma-ray data of OJ 287 for the period of 2017-2020. There
are several high states in optical-UV and X-ray frequencies during this period.
Based on the observed variability in optical and X-ray frequencies the entire
period 2017-2020 is divided into five segments, referred to as A, B, C, D, & E
in this paper. A detailed temporal and spectral analysis is performed to
understand the nature of its flaring activities. Methods. To understand the
temporal variability in this source we have studied the intra-day, and
fractional variability for all the various states, and along with that fast
variability time was also estimated to understand the nature of variability.
Further, the multi-wavelength SED modeling is performed to know more about the
physical processes responsible for the simultaneous broadband emission and the
fast variability. Results. The Fermi-LAT observations show a moderate flux
level of this source in gamma-ray frequency throughout this period, though flux
variability has been observed. The source has shown a strong flux variability
in X-ray, optical, and UV during early 2017 and mid-2020 when the source was in
a very high state. A single zone SSC emission model is considered to model the
spectral energy distributions and this helps us to explore the nature of this
BL Lac with binary super-massive black holes.
