TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3502
SUBJECT: Swift-BAT GRB 050528: a soft burst
DATE:    05/05/28 19:48:57 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <Scott@lheamail.gsfc.nasa.gov>

J. Cummings (GSFC/NRC), L. Barbier, S. Barthelmy (GSFC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD),
H. Krimm (GSFC/USRA), C. Markwardt, (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC), G. Sato (ISAS), M. Suzuki (Saitama),
T. Takahashi (ISAS), J. Tueller (GSFC)
on behalf of the Swift-BAT team:

The full data set has been delivered (GCN 3501).
Analysis of the data has allowed us to determine that Trigger 130649
at 04:06:45 UT (GCN 3496) is a real GRB.  The ground-analysis position
is RA,Dec 353.515,+45.938 (J2000) with an uncertainty of 3 arcmin
(radius, 90%, statistical plus systematic).

The lightcuve shows a single smooth peak lasting ~12 sec with an ~1-sec spike
riding on top towards the end of the event.  It starts ~T-8 and ends at T+4 sec.
T90 is 10.8 sec.

The burst spectrum is consistant with a simple power-law with a photon index
of 2.44 +-0.25 and a flux of 11.8 +-0.1 ph/cm2/sec (15-350 keV, 90% c.l.).
This is a very soft event with essentially no emission above 100 keV.
The fluence is (5.1+-0.1)x10^-7 ergs/cm2 (15-350 keV, 90% c.l.).