TITLE:   GCN CIRCULAR
NUMBER:  10462
SUBJECT: GRB 100302A, Swift-BAT refined analysis
DATE:    10/03/03 03:09:06 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-60 to T+243 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 100302A (trigger #414592)
(Cummings, et al., GCN Circ. 10458).  The BAT ground-calculated position
is RA, Dec = 195.504, 74.568 deg which is
    RA(J2000)  =  13h 02m 01.0s
    Dec(J2000) = +74d 34' 04.0"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 98%.

The mask-weighted light curve shows one group of multiple overlapping
peaks from T+40 to T+70.  T90 (15-350 keV) is 17.9 +- 1.7 sec (estimated
error including systematics).

The time-averaged spectrum from T+47.6 to T+67.3 sec is best fit by a
simple power-law model.  The power law index of the time-averaged
spectrum is 1.72 +- 0.19.  The fluence in the 15-150 keV band is
3.1 +- 0.4 x 10^-07 erg/cm2.  The 1-sec peak photon flux measured from
T+63.87 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec.  All the
quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/414592/BA/