TITLE:   GCN CIRCULAR
NUMBER:  19120
SUBJECT: GRB 160228A: Mondy optcial observations
DATE:    16/02/29 19:42:16 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@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 Swift GRB 160228A (Malesani et al., GCN 19107) 
with AZT-33IK telescope of Sayan observatory (Mondy)  starting on Feb.28 
(UT) 18:31:31. Within enhanced XRT position (Beardmore et al., GCN 
19110) we do not detect any optical object. In particular  we do not 
detect candidate of optical afterglow (Delvaux et al., GCN 19114). We 
barely detect extended bluish object mentioned in (Delvaux et al., GCN 
19114). Preliminary photometry  of  a combined image is following


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

2016-02-28  18:31:31  0.06044  R       60*60  22.2

Photometry is base on nearby USNO-B1.0 stars
USNO-B.1_id     R2
1169-0155723    18.59
1169-0155657    19.12
1169-0155662    18.92
1168-0146568    18.65
1169-0155709    19.49