GCN Circular 41333

S. D. Barthelmy (GSFC), R. Gupta (GSFC), 
N. J. Klingler (GSFC/UMBC/CRESSTII), 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-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 250807B (trigger #1340561)
(Klingler, et al., GCN Circ. 41268
Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 15.611, -59.098 deg which is 
   RA(J2000)  =  01h 02m 26.7s 
   Dec(J2000) = -59d 05' 52.2" 
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 64%.
 
The mask-weighted light curve displays a complex structure with several pulses.
The T90 (15-350 keV) is 104.17 +- 29.17 sec (estimated error including systematics).
 
The time-averaged spectrum from T-51.00 to T+85.16 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.72 +- 0.12.  The fluence in the 15-150 keV band is 2.5 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-48.59 sec in the 15-150 keV band
is 0.9 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1340561