GCN Circular 29199

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), B. Sbarufatti (PSU)
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(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 201229A (trigger #1015088)
(Sbarufatti et al., GCN Circ. 29192
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 210.692, 48.209 deg which is
   RA(J2000)  =  14h 02m 46.1s
   Dec(J2000) = +48d 12' 33.0"
with an uncertainty of 2.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.

The mask-weighted light curve shows a multi-peaked structure that
starts at ~T-45 s and ends at ~T+15 s. There is a weak pulse occurring
at ~T-40 s, followed by the main peak at ~T0. T90 (15-350 keV)
is 53.3 +- 4.6 sec (estimated error including systematics).

The time-averaged spectrum from T-44.43 to T+13.62 sec is best fit
by a simple power-law model.  The power law index of the time-averaged
spectrum is 1.40 +- 0.29.  The fluence in the 15-150 keV band is
1.3 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from
T+0.41 sec in the 15-150 keV band is 1.7 +- 0.4 ph/cm2/sec.  All the quoted
errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1015088/BA/