GCN Circular 3819

D.B. Fox (PSU), S. Barthelmy (GSFC), H. Krimm (GSFC/USRA), D. Burrows
(PSU), A. Blustin (UCL-MSSL), N. Gehrels (GSFC), J. Osborne
(U. Leicester), J. Kennea (PSU), T. Sakamoto (GSFC/NRC), P. Roming
(PSU) report on behalf of the Swift team:

At 12:19:58 UT, Swift-BAT triggered and located GRB050817
(trigger=150823).  The BAT on-board calculated location is RA,Dec
285.028 d, -24.930 d {19h 00m 07s, -24d 55' 48"}, with an uncertainty
of 2 arcmin (radius, 90%-containment, stat+sys).  The BAT light curve
shows a single peak of about 4 seconds duration.  The peak count rate
was ~600 counts/sec (15-350 keV) at ~2 seconds after the trigger.

Swift was unable to slew to the source due to the moon constraint.
X-ray telescope and UV/optical telescope observations of this region
will become possible at about 06:00 UT on 18 August 2005.

We note that the BAT position is 43 arcsec from the position of the
2.65-ms accreting X-ray pulsar HETE J1900.1-2455 (Vanderspek et
al., ATEL #516; Fox, ATEL #526).  Thus we cannot rule out that this
BAT trigger is due to HETE J1900.1-2455.