[vsnet-grb-info 12386] GRB 120907A: optical observations of ISON-Kislovodsk

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13761
SUBJECT: GRB 120907A: optical observations of ISON-Kislovodsk 
DATE:    12/09/13 18:53:47 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

V. Nevski (ISON-Kislovodsk Observatory), A. Volnova (SAI MSU/IKI), I. 
Molotov (KIAM), A. Pozanenko (IKI)  report on behalf of larger 
collaboration:

We observed the field of  GRB 120907A (Racusin  et al., GCN 13716) with 
Santel-400AN (0.4-m f/3)  telescope Ïf ISON-Kislovodsk observatory  starting 
on  Sep. 07 (UT) 00:34:32, i.e. ~10.2 minutes after burst  trigger.  We took 
several unfiltered images  of 30 s and 60 s exposures.  In a stacked images 
we clearly detect optical afterglow of   GRB 120907A (Racusin  et al., GCN 
13716; Gorbovskoy et al., GCN 13718; Kruehler et al., GCN 13719). A 
preliminary photometry of  stacked  frames is based  on the USNO-B1.0 (R2) 
nearby  stars:

T_start,     T0+,       Exp,     Filter,       OT
(UT)          mid (d)   (s)

00:34:32  0.00899 10x30    none      18.55+/-0.09
00:51:45  0.02120   5x60    none      18.95+/-0.13
00:58:09  0.02980   8x60    none      19.52+/-0.20
01:16:32  0.04339   8x60    none      19.50+/-0.20