GCN Circular 5795
Subject
GRB 061110: Swift detection of a burst
Date
2006-11-10T12:22:08Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
A. D. Falcone (PSU), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
S. Campana (INAF-OAB), M. M. Chester (PSU),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), T. Mineo (INAF-IASFPA), C. Pagani (PSU),
D. M. Palmer (LANL), M. Perri (ASDC),
P. Romano (Univ. Bicocca & INAF-OAB), G. Sato (GSFC/ISAS) and
L. Vetere (PSU) report on behalf of the Swift Team:
At 11:47:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 061110 (trigger=238108). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA,Dec 336.304, -2.267 {22h 25m 13s, -02d 16' 00"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows multiple peaks
with a duration of about 30 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 11:48:30 UT, 69 seconds after the
BAT trigger. XRT found a bright, fading, uncatalogued X-ray source on-board.
The ground-calculated position, based on quick-look data products, is
RA(J2000) = 22h 25m 10.0s, Dec(J2000) = -02d 15' 29.1", with an
estimated uncertainty of 4.3 arcseconds (90% confidence radius).
This location is 55.8 arcseconds from the BAT on-board position, within
the BAT error circle. The initial flux in the 2.5s image was
5.2e-09 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 400 seconds with the V filter
starting 71 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image
covers 100% of the XRT error circle. The 3-sigma upper limit is 19.0
mag. The 8'x8' region for the list of sources generated on-board
covers 100% of the XRT error circle. The list of sources is typically
complete to about 18.0 mag. No correction has been made for the
expected extinction of about 0.3 magnitudes.
We note that there are at least 35 galaxies within 10 arcmin
of the burst position.