TITLE:   GCN CIRCULAR
NUMBER:  17256
SUBJECT: GRB 141229A Swift-BAT observations
DATE:    14/12/30 18:33:53 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings, S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):


GRB 141229A (Fujita et al., GCN 17246) occurred during a preplanned Swift slew
maneuver.  A mosaic of BAT images at the time of the burst contains a
significant source consistent with the XRT afterglow position (Bernardini
et al., GCN 17251).  The partial coding was 6%.

The mask-weighted light curve shows a single FRED-shaped peak.  T90 (15-350 keV)
is 7 +- 1 sec (estimated error including systematics).

The time-averaged spectrum in 8 seconds is best fit by a simple power-law model.
The power law index of the time-averaged spectrum is 1.29 +- 0.17.  The fluence
in the 15-150 keV band is 1.5 +- 0.3 x 10^-6  erg/cm2.  The 1-sec peak photon flux
measured in the 15-150 keV band is 1.2 +- 0.5 ph/cm2/sec.  All the quoted errors
are at the 90% confidence level.

Since this burst was not detected onboard, the usual automated BAT data
products are not available.