[vsnet-grb-info 18232] GRB 160625B: TSHAO optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19680
SUBJECT: GRB 160625B: TSHAO optical observations
DATE:    16/07/11 12:56:47 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 on July 
8 and 10. 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)

2016-07-08 19:01:43   12.9172 R       30*300 21.60  0.15  22.7
2016-07-10 18:19:18   14.8713 R       29*300 21.64  0.08  23.3


Photometry is based on nearby USNO-B1.0 stars reported in GCN 19605 
(Mazaeva et. al).