TITLE:   GCN CIRCULAR
NUMBER:  36566
SUBJECT: GRB 240529A: Swift-BAT refined analysis
DATE:    24/05/29 17:19:11 GMT
FROM:    Tyler Parsotan  at NASA GSFC <tyler.parsotan@nasa.gov>

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) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240529A (trigger #1231488)
(Eyles-Ferris et al., GCN 36556).  The BAT ground-calculated position is
RA, Dec = 335.341, 51.557 deg which is
   RA(J2000)  =  22h 21m 22.0s
   Dec(J2000) = +51d 33' 25.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.

The mask weighted lightcurve shows a complex lightcurve structure with a relatively
gradual rise to the peak at trigger time and multiple pulses present at late times,
at t ~30 and ~50 sec after the trigger time.

T90 (15-350 keV) is 160.67 +- 14.52 sec (estimated error including systematics).
The time-averaged spectrum from -74.8 to 226.4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.68 +- 0.04.  The fluence in the 15-150 keV band is 2.1 +- 0.0 x 10^-05 erg/cm2.
The 1-sec peak photon flux measured from T+0.17 sec in the 15-150 keV band
is 7.7 +- 0.6 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/1231488