GCN Circular 14232

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
  
Using the data set from T-0 to T+10 sec, we report further analysis of BAT
GRB 130216B (trigger #548918) (Cummings, GCN Circ. 14226
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 ).  The BAT ground-
calculated position is RA, Dec 58.866, +2.036, which is:
RA (J2000)   03h 55m 27.9s
Dec (J2000)  02d 02m 10s
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 11%.
  
The mask-weighted light curve shows two peaks, the smaller from T+0 to T+2 and
the larger from T+2 to T+4.  Each is symmetrical in time.  T90 (15-350 keV) is
3.7 +- 0.5 sec (estimated error including systematics).
  
The time-averaged spectrum from T+0 to T+4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.77 +- 0.08.  The fluence in the 15-150 keV band is 1.3 +- 0.3 x 10^-6  erg/cm2.
The 1-sec peak photon flux measured from T+2.5 sec in the 15-150 keV band
is 7.4 +- 0.6 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Because this burst was not located in onboard processing, the full burst
response was not initiated and not all of the normal data products are
available.  A Swift TOO to determine the position of the x-ray afterglow has
been approved,  and will take place once the source comes out of constraint on
February 19th.