TITLE: GCN CIRCULAR NUMBER: 19642 SUBJECT: GRB 160625B: SAO RAS monitoring DATE: 16/07/02 13:55:29 GMT FROM: Vladimir Sokolov at SAO RAS A. F. Valeev, A. S. Moskvitin, G. M. Beskin, V. V. Vlasyuk, V. V. Sokolov (SAO RAS, Russia) report on behalf of the larger GRB follow-up team. We observed the GRB160625B field (Dirirsa et al. GCNC #19580) with two optical telescopes of SAO RAS: the 6-m BTA + Scorpio (B, V, Rc, Ic bands), and the 1-meter telescope Zeiss-1000 + CCD photometer (Rc band) at the June 29/30 night. We clearly detected an OT (Troja et al. ,GCNC #19588; Karpov et al GCNC #19603; Alexander et al. GCNC #19606) in our stacked frames. Preliminary Rc band results are shown in the following table. These estimations are based on the R2 magnitudes of the same nearby USNO-B1 stars as in our previous GCNC #19611. Mid_date, UT T-T0,d exp,s R_mag err Telescope ================================================================= June, 29.827 3.880 3 x 200 20.53 +/- 0.07 BTA June, 29.983 4.036 8 x 300 20.56 +/- 0.20 Zeiss-1000