GCN Circular 11152
Subject
GRB 100823A: optical observations
Event
Date
2010-08-27T20:23:43Z (15 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), A. Volnova (SAI MSU), B. Satovski (Astrotel), M.
Ibrahimov (MAO) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 100823A (Mangano et al. GCN 11135)
with AZT-22 telescope of Maidanak observatory. Several images in I-filter
were obtained starting on Aug. 23 (UT) 20:47:02.
We do not detect the object C (Levan et al. GCN 11145; Suzuki et al. GCN
11146) up to I=22.2m. We clearly detect both objects A and B (Levan et al.
GCN 11138). The photometry of stacked image is based on USNO-B1.0 star
0958-0013520 located at RA(J2000) = 01:22:45.50, DEC(J2000) = +05:49:03.0
and used as reference star in GCN 11140 (Guziy et al).
Object, t-T0, Filter, Exposure, OT, Upper
limit (3 sigma)
(mid, d) (s)
A 0.16605 I 19*180 21.06+/-0.09 22.2
B 0.16605 I 19*180 20.60+/-0.06 22.2
The photometry of the object A is compatible with photometry reported in
GCN 11146 (Suzuki et al).
Using photometry of the object C starting 5 minutes after burst (Suzuki et
al. GCN 11146) and upper limit I=22.2m at 0.16605 days one can estimate
power law decay index alpha > 1.25.
We thank Otabek Burhonov for performing the observations and for his
support.