GCN Circular 36543

A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC),
R. Gupta (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC),
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-239 to T+963 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 240523A (trigger #1230423)
(Siegel et al., GCN Circ. 36536
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 33.537, -22.053 deg which is
   RA(J2000)  =  02h 14m 08.9s
   Dec(J2000) = -22d 03' 10.6"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 47%.

The mask-weighted light curve shows a multi-peaked structure that
starts at ~T-6 s and ends at ~T+46 s. The main peak occurs at ~T+1 s.
T90 (15-350 keV) is 41.93 +- 8.66 sec (estimated error including
systematics).

The time-averaged spectrum from T-6.37 to T+46.30 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
2.07 +- 0.20.  The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T+0.18 sec in the 15-150 keV band
is 1.0 +- 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/1230423