GCN Circular 29080

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU)
(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 201216C (trigger #1013243)
(Beardmore et al., GCN Circ. 29061
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 ).  The BAT ground-calculated position is
RA, Dec = 16.364, 16.538 deg which is
   RA(J2000)  =  01h 05m 27.4s
   Dec(J2000) = +16d 32' 16.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 18%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~ T-16 s and ends at ~T+64 s. The main peak occurs at ~T+20 s.
T90 (15-350 keV) is 48.0 +- 16.0 sec (estimated error including
systematics).

The time-averaged spectrum from T-15.89 to T+64.11 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.43 +- 0.03.  The fluence in the 15-150 keV band is 4.5 +- 0.1 x 10^-5
erg/cm2.
The 1-sec peak photon flux measured from T+23.61 sec in the 15-150 keV band
is 18.0 +- 1.1 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/1013243/BA/