Optical activity of blazar OJ287

We perform optical photometric and R-band polarimetric monitoring of BL Lac object OJ 287 using 70-cm AZT-8 (CrAO, Ukraine) and 0.4-m LX-200 (St.Petersburg, Russia) telescopes, as a part of GASP/WEBT project. As reported in Atel#3680, this blazar was found by Fermi LAT in active state on 2011 October 10. Our data show that a sharp optical maximum was reached on the date 2011-10-07UT03, R=14.19, while on 2011-10-10UT02 R=14.74. Meanwhile highest optical polarization p= 21% was reached even before the optical maximum, in the night of October 6. Current high activity state of OJ287, with unexpected sign of time lag between optical and gamma-rays, deserves close attention in all wavelengths.

Astronomer's Telegram #3681
V. Larionov, D. Morozova, E. Larionova, D. Blinov (St. Petersburg Univ., Russia)
on 13 Oct 2011; 13:14 UT