GCN Circular 6359
Subject
GRB 070429B: ROTSE-III Optical Limits
Date
2007-04-29T03:56:35Z (18 years ago)
From
Brad Schaefer at LSU <schaefer@grb.phys.lsu.edu>
B. E. Schaefer (Louisiana State), W. Rujopakarn (U Mich), E.S. Rykoff (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-burst GRB 070429B (Swift trigger 277582; Markwardt
et al. GCN 6358), producing images beginning 7.9 s after the GCN notice
time. An automated response took the first image at 03:09:30.9 UT, 26.5 s
after the burst, under excellent conditions. We took 10 5-sec, 10 20-sec
20 60-sec exposures, and observations are continuing. 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 BAT error circle and within the error circle for the possible XRT
source, for both single images and coadding into sets of 10; the field is
not crowded. Individual images have limiting magnitudes ranging from
15.5-17.5; we set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
03:09:30.9 03:09:35.9 5 15.5 26.5 N
03:09:30.8 03:10:56.5 85 17.3 26.4 Y
03:27:43.5 03:39:11.4 687 18.5 1119.1 Y