[vsnet-grb-info 18171] GRB 160625B: TSHAO optical observations

[GCN Circulars]

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  <apozanen at iki.rssi.ru>

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).