GCN Circular 18183
Subject
KAIT Optical Upper Limits for GRB 120422A, 120724A, 120803B, 120911A, and 120923A
Date
2015-08-20T18:55:59Z (9 years ago)
From
Xiang-Gao Wang at GuangXi U <wangxg@gxu.edu.cn>
Xianggao Wang (UC Berkeley, GXU, UNLV), WeiKang Zheng,
Alexei V. Filippenko (UC Berkeley), and S. Bradley Cenko
(GSFC) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRBs 120422A (Troja et al.,
GCN 13243), 120724A (D'Avanzo et al., GCN 13510), 120803B
(Racusin et al. GCN 13566), 120911A (Cannizzo et al., GCN 13744),
and 120923A (Yershov et al., GCN 13796) at 510 s, 202 s, 196 s, 147 s,
and 236 s after the burst, respectively. Observations were performed
with an automatic sequence in the clear (roughly R), V, and I filters,
and the exposure time was 20 s per image. We do not detect any new
sources within the XRT error circles. We estimate the following upper
limits (magnitudes) in clear-band images for each GRB calibrated to
USNO B1.0:
GRB Start-Time Coadd-Images Mid-time Upper-Limit (3 sigma)
120422A 510 s 20 s x 6 758 s 20.6
120724A 202 s 20 s x 10 647 s 20.7
120803B 196 s 20 s x 10 644 s 21.7
120911A 147 s 20 s x 6 501 s 20.9
120923A 236 s 20 s x 6 563 s 21.0