GCN Circular 8293
Subject
GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
Date
2008-09-28T15:58:35Z (16 years ago)
From
Eli Rykoff at UCSB <erykoff@physics.ucsb.edu>
E.S. Rykoff (UCSB), F. Yuan (U Mich), T.A. McKay (U Mich), report on
behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded
to GRB 080928A (Swift trigger 326115, GCN 8292, Sakamoto et al.). The
first image was at 15:03:44.9 UT, 132.0 s after the burst (7.9 s after
the GCN notice time). The unfiltered images are calibrated relative to
USNO A2.0. Our initial images did not detect the UVOT counterpart to a
limiting magnitude of ~17.2. However, after ~500 seconds the source
brightened to 16.9 mag, and it brightened again at ~2000 s to ~16.2 mag.
The coordinates of the source are consistent with the UVOT counterpart:
06:20:17.0 -55:11:58.8 (J2000), with positional
uncertainty of 1" or better
start UT mag mlim(of image)
----------------------------------
15:19:02.3 16.9 16.9
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/gsb326115_3a04_img.jpg
Continuing observations are in progress.
