GCN Circular 9626
Subject
GRB 090709: ROTSE-III Optical Limits
Date
2009-07-09T08:32:56Z (16 years ago)
From
Fang Yuan at ROTSE <yuanfang@umich.edu>
S. B. Pandey (U Mich), W. Rujopakarn (Steward), H. Flewelling (IfA/
Hawaii), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), report on
behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
090709 (Swift trigger 356890; Morris D. C., GCN 9625), producing
images beginning 5.6 s after the GCN notice time. An automated
response took the first image at 07:39:00.6 UT, 26.0 s after the
burst, and during the gamma-ray emission, under good conditions. We
took 10 5-sec and 50 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 or the XRT error circle, for both
single images and coadding into sets of 10. Individual images have
limiting magnitudes ranging from 16.4-17.2; we set the following
specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
07:39:00.6 07:39:05.6 5 16.5 26.0 N
07:39:00.6 07:40:07.7 67 17.8 26.0 Y
07:40:20.2 07:45:02.4 282 18.2 105.6 Y