GCN Circular 13797
Subject
GRB 120923A: ROTSE-III Optical Limits
Date
2012-09-23T05:41:38Z (12 years ago)
From
Weikang Zheng at U.of Michigan <zwk@umich.edu>
W. Zheng (U Mich) and T. Guver (Sabanci U) report on behalf of the ROTSE
collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 120923A
(Swift trigger 534402; Yershov et al., GCN 13796), producing images
beginning 0.7 s after the GCN notice time. An automated response took the
first image at 05:17:43.7 UT, 97.4 s after the burst, under fair conditions.
We took 10 5-sec, 10 20-sec and 0 60-sec exposures. These unfiltered images
are calibrated relative to USNO A2.0 (R). Imaging is on going.
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle. Individual images have limiting magnitudes
ranging from 15.4-16.3; we set the following specific limits.
start UT end UT t_exp(s) mlim Coadd?
------------------------------------------------------
05:17:43 05:17:48 5 15.6 N
05:17:55 05:18:00 5 15.4 N
05:18:07 05:18:12 5 15.7 N
05:17:43 05:19:31 50 16.4 Y