[vsnet-grb-info 13244] GRB 130502A: optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14581
SUBJECT: GRB 130502A: optical upper limit
DATE:    13/05/05 22:25:32 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

V. Rumyantsev (CrAO), K.Antoniuk (CrAO), A. Pozanenko (IKI) report on 
behalf of larger GRB follow-up collaboration:

We observed the field of the Swift GRB 130502A (Troja et al., GCN 14527) 
with AZT-11 telescope of CrAO observatory on May 02 starting on (UT) 
18:20:46, i.e. ~30 min after burst trigger. We took several images in 
R-filter of 180 s exposure.  Within enchanced XRT position (Beardmore et 
al., GCN  14536) we do  not detect any source. Preliminary photometry of 
a combined image is following

T_start (UT)           T0+     Filter  Exp. OT  UpperLimit (3 sigma)
                        mid,days        s

2013-05-02T18:20:46.18 0.0419  R      3600  n/d 20.8

The photometry is based on USNO-B1.0  star 0898-0181247
09 14 15.80 -00 08 13.7 assuming R=18.02.