Brightness of OJ 287 seems to increase again in optical band
ATel #13755; R. Hosokawa, R. Adachi, K. L. Murata, M. Niwano, F. Ogawa, N. Nakamura, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
on 23 May 2020; 08:01 UT
Credential Certification: Katsuhiro Murata (murata@hp.phys.titech.ac.jp)
Subjects: Optical, AGN, Black Hole, Blazar, Quasar
Referred to by ATel #: 13785
Since the beginning of March 2020, the blazar OJ 287 has been in bright outburst in UV, X-rays, optical and radio (ATel #13658, #13637, #13702). It reached its optical maximum around MJD 58963 and started to show decreasing (ATel #13677).
We have been monitoring OJ 287 during the outburst with the optical three colors (g', Rc, and Ic) using the MITSuME 50 cm Telescopes at Akeno Observatory and Okayama Astrophysical Observatory in Japan, and confirmed the beginning of the bright outburst, the reach at maximum and the decrease in all filters.
In the last few nights, our data shows that the brightness seems to have stopped declining and started increasing around MJD 58985. We obtained the preliminary magnitudes of OJ 287 as follows:
g'=14.5+/-0.03, Rc=14.0+/-0.02, Ic=13.4+/-0.03 on 2020-05-13 (MJD 58982.55),
g'=14.2+/-0.04, Rc=13.7+/-0.03, Ic=13.2+/-0.03 on 2020-05-21 (MJD 58990.50).
We used the PS1 catalog for the flux calibration. The magnitudes are expressed in the AB system. We will continue simultaneous multi-color observation with the MITSuME telescope.
The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al., in prep; https://github.com/MNiwano/Eclair).
