GCN Circular 10075
Subject
GRB 091024: KAIT optical afterglow observations
Date
2009-10-25T02:54:09Z (15 years ago)
From
Ryan Chornock at UC Berkeley <chornock@astro.berkeley.edu>
R. Chornock, W. Li, and A. V. Filippenko (UC Berkeley) report on behalf of the
KAIT GRB team:
The Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory automatically
responded to the Swift BAT trigger for GRB 091024 (Marshall et al., GCN 10062)
with a sequence of observations starting 82 s after the BAT trigger. The
afterglow is not initially detected. Our first detection of the optical
afterglow (Mundell et al., GCN 10063) is in a 20 s I band observation starting
at 08:58:45 UT. The KAIT position is
(J2000) 22:36:59.64 +56:53:24.0
which is consistent the positions reported by Mundell et al. (GCN 10063) and
Henden et al. (GCN 10073). The optical afterglow is thereafter detected in a
sequence of V, I, and unfiltered images as it rose to a peak at an unfiltered
magnitude of 16.2 (preliminarily calibrated to USNO-B1) at t=404s and then
declined to mag 17.0 at t=988s, similar to the behavior described by Cano et al.
(GCN 10066). After this time observations ceased due to a pointing limit.