GRB 071020A
GCN Circular 6948
Subject
GRB 071020A: ROTSE-III Detection of Optical Counterpart
Date
2007-10-20T07:17:21Z (18 years ago)
From
Brad Schaefer at LSU <schaefer@grb.phys.lsu.edu>
B. E. Schaefer (Louisiana State), T.A. McKay (U Mich), F. Yuan (U Mich),
report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
071020A (Swift trigger 294835). The first image was at 07:02:52.5 UT, 25.6
s after the burst (9.5 s after the GCN notice time). The unfiltered images
are calibrated relative to USNO A2.0. We detect a 13.6 magnitude, fading
source with coordinates:
07:58:39.9 +32:51:41.4 (J2000), with positional uncertainty
of 1" or better
start UT mag mlim(of image)
----------------------------------
07:02:52.9 13.6 16.4
This source is not visible in DSS (second epoch), 2MASS or the MPChecker
database.
A jpeg image is available at
http://www.rotse.net/images/gsb294835_3b00_img.jpg
Continuing observations are in progress.
GCN Circular 6953
Subject
GRB 071020A: IR Imaging with PAIRITEL
Date
2007-10-20T16:20:34Z (18 years ago)
From
Josh Bloom at UC Berkeley <jbloom@astron.berkeley.edu>
J. S. Bloom, D. A. Perley (UC Berkeley) and D. L. Starr (UC Berkeley,
LCOGT) report:
"We observed the field of the optical transient (Schaefer et al. GCN
6948) of GRB 071020A (Holland et al. GCN 6949) with the 1.3m PAIRITEL
on Mt. Hopkins starting at 2007-10-20 09:18 UT (~2h16m after the GRB,
once the field was within telescope limits). In a stack of 2190 sec
total integration time (mean time = 2007-10-20 09:46 UT), we detect
the source in the J-band at position:
ra= 07:58:39.78 dec = +32:51:40.4
(J2000; rms uncertainty relative to 2MASS of 250 mas in each
coordinate) with J=19.06 +/- 0.23 mag and H=18.71 +/- 0.30 (only
marginally detected). The source appears to have faded in subsequent
imaging."
This message may be cited.
GCN Circular 6956
Subject
GRB071020A: Xinglong TNT Optical afterglow observations
Date
2007-10-20T22:33:55Z (18 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng,
J. Wang, Y. Urata and W.K. Zheng on behalf of EAFON report:
We have imaged the field of GRB071020A (Barthelymy et al
GCN6949) using the TNT 0.8 telescope at Xinglong observatory.
A series of R-band images were obtained from 17:08:19.4,
10.1 hours after the burst.
In our 15*600s combined image, �we detected afterglow
(Schaefer et al GCN6947, Beardmore et al GCN 6955),
The estimated brightness derived from USNO-B1.0 was
R=21.14 +/- 0.08 at 11.5 hours after the burst
(mean time of the stacked image).
Further observations are encouraging.
This message may be cited.