GCN Circular 5752
Subject
GRB 061025: ROTSE-III Optical Limits
Date
2006-10-25T19:55:31Z (18 years ago)
From
Eli Rykoff at U of Michigan/ROTSE <erykoff@umich.edu>
E.S. Rykoff (U Mich), B. E. Schaefer (Louisiana State), R. Quimby (U
Texas), H. Swan (U Mich), S.A. Yost (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 GRB 061025 (Integral trigger 3525, Mereghetti, et al, GCN
5751), producing images beginning 4.6 s after the GCN notice time. An
automated response took the first image at 18:36:46.6 UT, 44.7 s after
the burst, under excellent conditions. We took 10 5-sec, 10 20-sec and
31 60-sec eposures. These unfiltered images are calibrated relative to
USNO A2.0 (R).
Comparison to the DSS (second epoch) reveals no new sources within the
90% INTEGRAL error circle, for both single images and coadding into sets
of 10; however, we are limited as the field is somewhat crowded. We
note that the bright elliptical galaxy NGC 6851 is in the error box.
Individual images have limiting magnitudes ranging from 13.3-16.9; we
set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
18:36:46.6 18:36:51.6 5 15.2 44.7 N
18:36:46.6 18:39:01.9 135 16.9 44.7 Y
18:39:11.4 18:43:57.0 285 17.5 189.5 Y