Skip to main content
Announcing GCN Classic Migration Survey, End of Legacy Circulars Email. See news and announcements

GCN Circular 4455

Subject
GRB 060109: Swift Detection of a long burst
Date
2006-01-09T17:31:48Z (19 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
M. De Pasquale (MSSL), S. Barthelmy (GSFC), A. Beardmore (U. Leicester),
J. Cummings (GSFC/ORAU), N. Gehrels (GSFC), M.R. Goad (U. Leicester),
O. Godet (U. Leicester), J. Kennea (PSU), H. Krimm (GSFC/USRA),
F. Marshall (GSFC), K. Page (U. Leicester), D. Palmer (LANL),
T. Sakamoto (GSFC),
on behalf of the Swift Team:

At 16:54:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060109 (trigger=176620).   The BAT on-board calculated
location is RA,Dec 282.710, +31.989 {18h 50m 50s, +31d 59' 22"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 10 sec.  The peak count rate was
~1000 counts/sec (15-350 keV), at ~8 sec after the trigger.

The XRT began observing the burst at 16:56:22 UT, 101 sec after the BAT
trigger.  A bright (0.2-10 keV flux of 4.8e-09 erg/cm2/sec), fading,
uncatalogued source was found by the on-board centroiding algorithm at
RA(J2000)= 18h 50m 43.9s
DEC(J2000)= +31d 59' 34.7"
with an uncertainty of 5.8 arcsec radius (90% containment).  This
uncertainty includes a systematic error of about 5 arcsec in the
on-board calculated positions due to the XRT boresight offset.  This
position lies 84 arcsec from the centre of the BAT error circle.

UVOT took a finding chart exposure of 200 seconds with the V filter
starting 104 sec 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 typical 3-sigma upper limit has been
about 18th 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 19.0 mag. No correction has been made for
the expected visual extinction of about 0.5 magnitudes.
Looking for U.S. government information and services? Visit USA.gov