[vsnet-grb-info 18021] GRB 160525B: Khureltogot optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19469
SUBJECT: GRB 160525B: Khureltogot optical upper limit
DATE:    16/05/26 18:06:16 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Mazaeva (IKI), S. Schmalz (ISON), A. Volnova (IKI),  N. Tungalag 
(Research Center of Astronomy and Geophysics MAS),   I. Molotov (KIAM),
A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of the GRB 160525B (Krimm et al., GCN  19459) with 
  ORI-40 telescope of Khureltogot observatory starting on May, 25 (UT) 
15:51:26.  We do not detect any source within enhanced Swift-XRT 
position (Beardmore et al., GCN 19463). Preliminary photometry  of  the 
combined image is following

Date        UT start   t-T0    Filter  Exp.    UpperLimit (3 sigma)
                       (mid, days)      (s)

2016-05-25  15:51:26   0.29070  clear  60*60  21.0

Photometry is based on nearby SDSS-DR9 stars, Lupton transformations into R:
SDSS-DR9_id            R(Lupton)
J095742.79+511301.4    16.17
J095737.78+511402.4    16.43
J095736.76+511019.5    14.87
J095730.61+510914.1    17.74
J095737.35+510856.0    15.01