GCN Circular 6795
Subject
GRB 070917: KAIT optical limits
Date
2007-09-17T23:05:15Z (17 years ago)
From
Weidong Li at UC Berkeley KAIT/LOSS <weidong@astron.berkeley.edu>
W. Li, University of California, Berkeley, on behalf of the KAIT GRB
team, report:
The robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT)
at Lick Observatory observed GRB 070917 detected with Swift
(Trigger 291292; Cummings et al. GCN 6791, Tueller et al. GCN
6792). The automatic sequence started at 07:34:52, 56 s after
the burst. The BAT location has been monitored in V, I, and
clear filters, with varying exposure times. Our image processing
pipeline did not find any new objects within the BAT error circle,
with the following photometry limits (calibrated with USNO B1.0).
These magnitudes have not been corrected for Galactic extinction
(E(B - V) = 0.45 mag; Misra et al. GCN 6793).
======================================================================
Start UT t(GRB) Filter Exp(s) 3sigma-limit
07:34:52 56s clear 5.0 16.8
07:34:58 62s clear 5.0 16.7
07:35:04 68s clear 5.0 16.8
07:35:10 74s clear 5.0 16.7
07:35:17 81s clear 5.0 16.9
07:35:48 112s V 20.0 16.2
07:36:19 143s I 20.0 17.3
07:36:49 173s clear 20.0 17.9
========================================================================
More images, mostly 20 s exposures in the I and clear filters,
have been obtained. No obvious OA was found in the BAT error
circle to a limiting magnitude of 16.9 - 18.0 mag, at
t= 204 s to 2204 s after the burst.
This message may be cited.