GCN Circular 5927
Subject
GRB 061217: ROTSE-III Optical Limits
Date
2006-12-17T04:34:39Z (18 years ago)
From
Brad Schaefer at LSU <schaefer@grb.phys.lsu.edu>
B. E. Schaefer (Louisiana State) reports on behalf of the ROTSE
collaboration:
ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe,
Turkey, responded to GRB 061217 (Swift trigger 251634), producing images
beginning 6.3 s after the GCN notice time. An automated response took the
first image at 03:40:26.3 UT, 18.1 s after the burst, under excellent
conditions. We took 10 5-sec, 10 20-sec and 20 60-sec eposures. These
unfiltered images are calibrated relative to USNO A2.0 (R). The last few
images have substantial background from twilight, and so our imaging has
now stopped in Turkey.
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma error circle, for both single images and coadding into sets of 10;
the field is not crowded. Individual images have limiting magnitudes
ranging from 15.3-16.9; we set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
03:40:26.3 03:40:31.3 5 15.3 18.1 N
03:40:26.3 03:42:34.5 128 17.2 18.1 Y
03:58:53.0 04:10:09.5 676 17.3 1124.8 Y