GCN Circular 16809
Subject
GRB 140907A: TShAO observations
Date
2014-09-09T20:54:38Z (10 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), A. Pozanenko (IKI), W. Mundrzyjewski (Fesenkov
Astrophysical Institute), V. Tereshenko (Fesenkov Astrophysical
Institute) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 140907A (Krimm et al., GCN
16788)with Zeiss-1000 (East) telescope of Tien Shan Astronomical
Observatory starting on Sep. 07, (UT) 17:05. We took several images in
R-filter. Within enhanced XRT error circle (Goadet al., GCN 16795) we
clearly detect the afterglow(Xu et al., GCN 16789; Kuin and Krimm, GCN
16791).
Preliminary photometry of first and last exposures is following
Date UT start t-T0,d Exp,s Filter OT OT_err
(mid)
2014-09-07 17:33:41 0.06357 600 R 18.94 0.08
2014-09-07 23:22:46 0.30598 600 R 20.22 0.07
The photometry is based on nearby USNO-B1.0 stars, R2 magnitudes.
Preliminary light curve of the afterglow of GRB 140907A obtained between
(UT) 17:33:41 and 23:22:46 can be found in
http://grb.rssi.ru/GRB140907A/GRB14907A_lc.png .
Within the time interval ( 17:33:41 - 23:22:46 ) the LC might be
approximated by power law with a power law index ~-2 which could suggest
the jet-brake within this interval.