GCN Circular 37356

D. M. Palmer (LANL), 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),
T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC),
T. Sakamoto (AGU) (i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240829A (trigger #1251252)
(Laha, et al., GCN Circ. 37333
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 143.079, -18.687 deg which is
   RA(J2000)  =  09h 32m 18.9s
   Dec(J2000) = -18d 41' 13.0"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 15%.
 
The mask-weighted light curve displays a combination of two to three dim fast-
rise-exponential-decay pulses. The T90 (15-350 keV) is 43.20 +- 10.47 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-12.53 to T+51.47 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.66 +- 0.11.  The fluence in the 15-150 keV band is 3.8 +- 0.3 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+10.97 sec in the 15-150 keV band
is 0.0 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Swift did not slew to the BAT position due to the burst being sun constrained.

The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1251252