[vsnet-grb-info 18022] GRB 160525B: Mondy optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19470
SUBJECT: GRB 160525B: Mondy optical upper limit
DATE:    16/05/26 18:08:31 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Mazaeva (IKI),  E. Klunko (ISTP), A. Volnova (IKI),   I. Korobtsev 
(ISTP),  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 
AZT-33IK telescope of Sayan observatory (Mondy)  starting on May, 25 
(UT) 15:54:47.  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  15:54:47   0.29111  R       30*120  22.6

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