GCN Circular 4094
Subject
GRB051006: optical observations
Event
Date
2005-10-14T15:15:37Z (20 years ago)
From
Vasilij Rumjantsev at CrAO <rum@crao.crimea.ua>
V.Rumyantsev (CrAO), V.Biryukov (SAI, MSU), A.Pozanenko (IKI), M. Ibrahimov
(MAO) on behalf of larger GRB follow up collaboration report:
We have observed the GRB051006 error box (Norris et al., GCN4061) with 2.6 m
Shajn telescope of CrAO on October 7 and 8 in R-band. On Oct.8 within XRT
error circle (Capalbiet al., GCN4066) we detect source #3 quoted by Ugarte
et al. (GCN 4064). The coordinate of the source is
RA(J2000) = 07 23 13.52
Dec = +09 30 24.48
with uncertainty 0.4 arcsec in both coordinates. The photometry of the
source against of USNO A2.0 is following
Mid time Exposure R
Oct.8 (UT)
02:28 35x120 s 22.20 +/-0.15
The stacked image of the Oct.8 observation can be found in
http://grb.rssi.ru/GRB051006/grb051006_051008_ZTSh_R.gif
Taking into account the upper limit of R>21.0 at 12.9 hours after the burst
(Bradley Cenko at al., GCN 4068) and our result above one can estimate the
power law decay index of possible afterglow source #3 as alpha >-1.37.
In our observation on Oct.7 between 02:23 - 02:44 (UT) due to unfavorable
weather conditions the seeing was ~5 arcsec. At this time we could not
confirm the presence of source #3 in the tail of nearby bright star.
Detailed analysis in underway.
This message can be cited.