TITLE:   GCN CIRCULAR
NUMBER:  37272
SUBJECT: GRB 240824A: Swift-BAT refined analysis
DATE:    24/08/25 14:48:57 GMT
FROM:    Amy <yarleen@gmail.com>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), S. B. Cenko (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) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 240824A (trigger #1250282)
(Cenko et al., GCN Circ. 37254).  The BAT ground-calculated position is
RA, Dec = 213.176, 63.735 deg which is
   RA(J2000)  =  14h 12m 42.3s
   Dec(J2000) = +63d 44' 06.7"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The
partial coding was 72%.

The mask-weighted light curve shows a complex structure that starts at ~T-1
s and ends at ~T+43 s. The main peak occurs at ~T+1 s. T90 (15-350 keV) is
39.47 +- 3.44 sec (estimated error including systematics).

The time-averaged spectrum from T-0.66 to T+43.40 sec is best fit by a
simple power-law model.  The power law index of the time-averaged spectrum
is 1.30 +- 0.14.  The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-6
erg/cm2. The 1-sec peak photon flux measured from T-0.02 sec in the 15-150
keV band is 0.7 +- 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/1250282