TITLE: GCN CIRCULAR NUMBER: 19619 SUBJECT: GRB 160625B: TSHAO optical observations DATE: 16/06/29 15:18:38 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), A. Kusakin (Fesenkov Astrophysical Institute), P. Minaev (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 160625B (Dirirsa et al., GCN 19580; Burns et al. GCN 19581) with Zeiss-1000 (East) 1-m telescopes of Tien Shan Astronomical Observatory. We obtained several images in R filter starting on June 27 (UT) 20:15:57. We detect optical afterglow of GRB 160625B (Troja et al., GCN 19588; Oates et al., GCN 19589). Preliminary photometry of a combined image is following Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2016-06-27 20:15:57 1.92994 R 54*60 19.56 0.06 22.0 Photometry is based on nearby USNO-B1.0 stars reported in GCN 19605 (Mazaeva et. al).