[vsnet-grb-info 12985] GRB 130313A: optical upper limit in CrAO

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14322
SUBJECT: GRB 130313A: optical upper limit in CrAO
DATE:    13/03/16 19:54:45 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

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

We observed the field of the Swift GRB 130313A (Gompertz  et al., GCN 
14293) with ZTSh telescope of CrAO observatory (Mondy) on March 14
between (UT) 00:23:52 - 02:11:00. We took several images in R-filter of 60 
s exposure which cover  the  refined BAT error box (Barthelmy et al., GCN 
14296). Within  XRT position (Gompertz et al., GCN  14297; Osborne et al., 
GCN  14300) we do  not detect any source. Preliminary photometry of a 
combined image is following

UT start,    t-t0           filter      Exp.   OT      UL (3 sigma)
             (mid, days)                (s)

00:23:52    0.3818        R     24x60   n/d     22.7

The photometry is based on USNO-B1.0  star
0896-0256107 15:45:37.83 -00:22:18.2 R=16.04