GCN Circular 10655
Subject
Swift Trigger 420256: ROTSE-III Optical Limits
Date
2010-04-23T03:31:22Z (15 years ago)
From
Limin Xiao at Louisiana State U <lxiao1@lsu.edu>
L. Xiao (Louisiana State), W. Zheng (U Mich), H. Flewelling (IfA/Hawaii),
report on behalf of the ROTSE collaboration:
ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded
to Swift trigger 420256, producing images beginning 7.5 s after the GCN
notice time. An automated response took the first image at 02:45:32.5 UT,
90.2 s after the burst. We took 10 5-sec, 10 20-sec and 10 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, for both single images and coadding into
sets of 10. Individual images have limiting magnitudes ranging from
15.9-17.3; we set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
02:45:32.5 02:46:48.9 76 17.1 90.2 Y
02:47:03.3 02:51:45.9 282 17.7 181.0 Y
02:51:54.6 03:03:15.0 680 17.9 472.3 Y