GCN Circular 41539

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
R. Gupta (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
M. J. Moss (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC),
T. Sakamoto (AGU), M. H. Siegel (PSU)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 250823A (trigger #1344586)
(Siegel, et al., GCN Circ. 41511
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 ).  The BAT ground-calculated position is
RA, Dec = 297.465, -24.986 deg which is
   RA(J2000)  =  19h 49m 51.7s
   Dec(J2000) = -24d 59' 09.0"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.

The mask-weighted BAT light curve shows multi-peaked emission 
starting from ~T-25 to ~T+180 sec.
T90 (15-350 keV) is 193.60 +- 10.19 sec (estimated error including systematics).

The time-averaged spectrum from T-23.84 to T+180.82 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.76 +- 0.16.  The fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+4.24 sec in the 15-150 keV band
is 1.1 +- 0.2 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/1344586