GCN Circular 5955
Subject
GRB 061222A: Prompt ROTSE-III Optical Limits
Event
Date
2006-12-22T04:01:17Z (19 years ago)
From
Eli Rykoff at U of Michigan/ROTSE <erykoff@umich.edu>
E.S. Rykoff (U Mich), 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
061222A (Swift trigger 252588, GCN 5954, Gruppe, et al), producing
images beginning 7.3 s after the GCN notice time. An automated response
took the first image at 03:29:39.3 UT, 47.1 s after the burst, under
excellent conditions. We took 10 5-sec, 10 20-sec and 10+ 60-sec
exposures. These unfiltered images are calibrated relative to USNO A2.0
(R). We note that several of our images, with limiting magnitudes ~17.0,
overlap the main peak in the BAT emission. Imaging is ongoing.
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma BAT error circle or the XRT error circle, for both single images
and coadding into sets of 10; however, we are limited as the field is
somewhat crowded. Individual images have limiting magnitudes ranging
from 16.5-18.0; we set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
03:29:39.4 03:29:44.4 5 16.5 47.2 N
03:30:14.4 03:30:19.4 5 17.0 82.2 N
03:30:21.4 03:30:26.4 5 17.0 89.2 N
03:29:39.4 03:30:47.4 68 18.1 47.2 Y
03:30:55.4 03:35:50.8 295 18.5 123.2 Y