TITLE:   GCN CIRCULAR
NUMBER:  38583
SUBJECT: GRB 241213A: Swift-BAT refined analysis
DATE:    24/12/16 20:57:10 GMT
FROM:    Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>

T. Sakamoto (AGU), 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), D. M. Palmer (LANL),
T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC),
(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 241213A (trigger #1274039)
(Gupta, et al., GCN Circ. 38547).  The BAT ground-calculated position is
RA, Dec = 116.163, 35.269 deg which is
   RA(J2000)  =  07h 44m 39.2s
   Dec(J2000) = +35d 16' 06.7"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 44%.
 
The mask-weighted light curve shows a single bright episode that starts
at ~T-11 s, peaks at ~T+1 s and ends at ~T+16 s.
T90 (15-350 keV) is 10.3 +- 3.1 sec (estimated error including systematics).
 
The time-averaged spectrum from T-10.79 to T+16.54 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.26 +- 0.06.  The fluence in the 15-150 keV band is 4.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.24 sec in the 15-150 keV band
is 10.3 +- 0.5 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/1274039