GCN Circular 10254
Subject
GRB 091208: ROTSE-III Optical Limits
Date
2009-12-08T09:16:45Z (15 years ago)
From
Fang Yuan at ROTSE <yuanfang@umich.edu>
F. Yuan (U Mich), W. Rujopakarn (Steward), W. Zheng (U Mich), report
on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
091208 (Swift trigger 378554; E. A. Hoversten et al, GCN 10253),
producing images beginning 9.6 s after the GCN notice time. An
automated response took the first image at 08:46:30.5 UT, 30.0 s after
the burst. We took 10 5-sec and 42 20-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, for both single images and coadding
into sets of 10. Individual images have limiting magnitudes ranging
from 14.6-16.6; we set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
08:52:40.1 08:57:21.5 281 17.3 399.6 Y
08:57:30.2 09:02:12.0 281 17.4 689.7 Y