[vsnet-grb-info 1960] GRB 050814: Swift detection of a burst

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3799
SUBJECT: GRB 050814: Swift detection of a burst
DATE:    05/08/14 12:35:37 GMT
FROM:    David Burrows at PSU/Swift  <dxb15 at psu.edu>

A. Retter (PSU), L. Barbier (GSFC), S. Barthelmy (GSFC), A. Blustin 
(UCL-MSSL), D. Burrows (PSU), C. Markwardt (GSFC/UMD), F. Marshall (GSFC), 
D. Morris (PSU), D. Palmer (LANL), J. Racusin (PSU), P. Roming (PSU), and 
N. Gehrels (GSFC) report on behalf of the Swift team:

At 11:38:57 UT, Swift-BAT triggered and located GRB050814
(trigger=150314).  The BAT on-board calculated location is
RA,Dec 264.204,+46.333, {+17h 36m 49s, +46d 19' 58"} (J2000),
with an uncertainty of 3 arcmin (radius, 90% containment,
stat+sys).  There is a single peak with an approximate
duration of 25 sec FWHM.  The peak rate is approx 800 ct/s in the
15-350 keV band.  We note that no BAT Position Notice was
distributed through the GCN for this burst.

The S/C slewed immediately and the XRT began taking data at 11:41:15, 138 s 
after the BAT trigger.  The XRT on-board centroid algorithm did not 
converge and no prompt position is available.  However, the lightcurve 
shows a bright, decaying source in the field of view, and the spectrum 
looks like a GRB.  We are waiting for down-linked data to determine a position.

The UVOT began observing at 11:41:43.9 UT, 167 s after the BAT trigger. In 
a 100 s V-band image, no new source is detected with respect to the DSS 
image down to a 5 sigma upper limit of 18.0 mag.