GCN Circular 9667
Subject
GRB 090715A: ROTSE-III Optical Limits
Date
2009-07-15T17:47:35Z (15 years ago)
From
Shashi Bhushan Pandey at ARIES, INDIA <shashi@aries.ernet.in>
S. B. Pandey (U Mich), S.A. Yost (College of St. Benedict), W. Zheng,
F. Yuan (U Mich), report on behalf of the ROTSE collaboration:
ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded to the short-hard GRB 090715A (Swift trigger 357498, Racusin J. L., GCN 9666), producing images
beginning 7.1 s after the GCN notice time. An automated response took
the first image at 17:26:05.1 UT, 25.9 s after the burst, under fair
conditions.
We took 10 5-sec and 10 20-sec exposures and imaging is ongoing.
These unfiltered images are calibrated relative to USNO A2.0 (R).
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 15.4-16.6; we
set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
17:26:05.1 17:27:21.5 76 16.8 25.9 Y
17:27:36.4 17:32:18.5 282 17.4 117.2 Y