[vsnet-grb-info 12548] GRB 121011A: optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13912
SUBJECT: GRB 121011A: optical observations
DATE:    12/10/27 23:02:08 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss at gmail.com>

A. Volnova (SAI MSU, IKI), Moskvitin (SAO RAS), V. Rumyantsev (CrAO),
A. Pozanenko (IKI)


We observed the field of the Swift GRB 121011A (Racusin et al., GCN
13845) with ZTSh telescope of CrAO on Oct. 15 between (UT) 17:36 and
18:54 under good weather condition with mean seeing of about 1.5
arcsec. We took 70 frames with exposure of 60 seconds in filter R.  In
a stacked image we do not detect any source within enhanced XRT error
circle (Evans et al., GCN 13850).

We also observed the field of this GRB with Zeiss-1000 telescope of
SAO RAS on Oct. 17 between (UT) 17:45 and 18:38 under good weather
conditions with mean seeing of about 2.4 arcsec. We took 12 frames
with exposure of 200 seconds. On a stacked image we do not detect any
source either. The photometry based on a USNO-B1 star #1310-0279773
(R1 = 17.84; same
as calibration in Fynbo et al., GCN Circ. 13856; Malesani et al., GCN
13853) is following:

T0+        Filter,  Exposure, OT,  UL (3 sigma),  Telescope
(days)               (s)

4.292      R       70x60        n/d   23.5                ZTSh
6.294      R       12x200      n/d   22.3                Zeiss-1000