Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 4281

Subject
GRB 051117B: Swift detection of a burst
Date
2005-11-17T13:59:44Z (19 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
D. Band (PSU), S. Barthelmy (GSFC), A. Beardmore (U Leicester),
D. Burrows (PSU), J. Cummings (GSFC/NRC), S.T. Holland (GSFC/USRA),
M. Goad (U. Leicester), O. Godet (U. Leicester), N. Gehrels (GSFC),
C. Gronwall (PSU), J. Kennea (PSU), H. Krimm (GSFC/USRA),
J. Osborne (U Leicester), K. Page (U Leicester)
on behalf of the Swift team:

At 13:22:54 UT, Swift-BAT triggered and located GRB 051117B (trigger=164279).
The BAT on-board calculated location is RA,Dec 85.225d,-19.245d
{05h 40m 54s,-19d 14' 41"} (J2000), with an uncertainty of 3 arcmin
(radius, 90% containment, stat+sys).  The BAT light curve shows
a multi-peak structure with a total duration of ~25 sec.  The peak count
rate was ~800 counts/sec (15-350 keV), at ~2 seconds after the trigger.

The spacecraft slewed immediately and the XRT began observing the GRB at
13:25:09 UT, 135 sec after the BAT trigger.  The on-board detection algorithm
did not centroid on a source due to insufficient counts, so no prompt X-ray
position is available.  However, the XRT prompt light curve and raw spectrum
look like a faint GRB.  More information will be available around 16:30 UT,
after the next Malindi ground-station pass.

UVOT took a finding chart exposure of 200 sec with the V filter
starting 133 sec after the BAT trigger.  No afterglow candidate
has been found in the initial data products.  The sub-image covers 19%
of the BAT error circle.  No afterglow candidate is found in the list
of sources generated on-board, which covers 89% of the BAT error circle.
The list of sources is typically complete to about 17th mag.  No correction
has been made for the expected visual extinction of about 0.19 magnitudes.
Looking for U.S. government information and services? Visit USA.gov