[vsnet-grb-info 11164] GRB 111117A: optical upper limit in CrAO

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12576
SUBJECT: GRB 111117A: optical upper limit in CrAO 
DATE:    11/11/20 15:51:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

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

We observed field of the Swift  GRB 111117A  (Mangano  et al. GCN 12559) 
with AZT-11 telescope of CrAO in R filter between Nov. 17 (UT) 16:11:05 - 
17:14:24, i.e. starting ~ 4 h after burst trigger. We took several images of 
180 exposure under variable weather conditions and mean seeing (FWHM) of 
about 2.7". We do not detect any source within XRT  position (Melandri  et 
al. GCN 12565). A photometry is based on the USNO B1.0  1130-0013895 star 
(00:50:46.48 +23:01:28.8) assuming R=16.98:

  T0+      Filter,   Exposure, OT,  UpperLimit
(mid, d)               (s)

0.1879   R         22x180       n/d   20.6