GCN Circular 13820
Subject
GRB 120923A: optical upper limit
Date
2012-09-26T20:24:47Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
L. Elenin (KIAM), A. Volnova (SAI MSU, IKI), I. Molotov (KIAM), A. Pozanenko
(IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 120923A (Yershov et al., GCN 13796)
with 0.45-m telescope of ISON-NM observatory starting on Sep. 23 (UT)
05:18:58, i.e 172 s after burst trigger. We took several unfiltered images
of 30 s and 60 s exposures. We do not detect the optical counterpart (Levan
et al., GCN 13802). A photometry of co-added frames is based on the
USNO-B1.0 (R2) nearby stars is following:
T0+, Exposure, OT, UL (3 sigma)
mid, d (s)
0.00447 9x30 n/d 19.7
0.02839 53x30 n/d 20.5