GRB 250424***A***, Swift-BAT refined analysis
 
<somebody goes first>
<add the BA alphabetically>
S. D. Barthelmy (GSFC), 
R. Gupta (GSFC),
H. A. Krimm (NSF),
S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC),
M. J. Moss (GSFC),
D. M. Palmer (LANL),
T. Parsotan (GSFC),
D. Sadaula (GSFC/UMBC),
T. Sakamoto (AGU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+600 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 250424***A*** (trigger #1306404)
(NAME, et al., GCN Circ. xxxx).  The BAT ground-calculated position is
RA, Dec = 217.532, -35.025 deg which is 
   RA(J2000)  =  14h 30m 07.6s 
   Dec(J2000) = -35d 01' 28.2" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.
 
[Description about the mask-weighted light curve]
T90 (15-350 keV) is 18.6 +- 0.7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-38.7 to T+17.2 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.58 +- 0.11, 
and Epeak of 120.4 +- 39.6 keV (chi squared 35.20 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.2 +- 0.0 x 10^-05 erg/cm2
and the 1-sec peak flux measured from T-14.85 sec in the 15-150 keV band is
47.2 +- 1.3 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.79 +- 0.03 (chi squared 46.92 for 57 d.o.f.).  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/1306404/BA/