GRB 240227***A***: Swift-BAT refined analysis
 
<somebody goes first>
<add the BA alphabetically>
S. D. Barthelmy (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),
T. Sakamoto (AGU)
(i.e. the Swift-BAT team):
 
Using the data set from T-441 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240227***A*** (trigger #1217729)
(NAME, et al., GCN Circ. xxxx).  The BAT ground-calculated position is
RA, Dec = 245.379, -15.636 deg which is 
   RA(J2000)  =  16h 21m 30.9s 
   Dec(J2000) = -15d 38' 10.1" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.
 
[Description about the mask-weighted light curve]
T90 (15-350 keV) is 80.00 +- 0.00 sec (estimated error including systematics).
 
The time-averaged spectrum from TTBD to TTBD sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
5.38 +- 0.50.  The fluence in the 15-150 keV band is 6.9 +- 0.7 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.00 sec in the 15-150 keV band
is 0.3 +- 0.0 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/1217729