GCN Circular 6551
G. Sato (GSFC/ISAS) and S. Barthelmy (GSFC) on behalf of the Swift-BAT team: The time-averaged spectrum from T-2.6 to T+602.2 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.61 +- 0.04. The fluence in the 15-150 keV band is 1.92 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+139.74 sec in the 15-150 keV band is 1.9 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The mask-weighted light curve shows many peaks. The burst started with a low-level smooth emission at ~T-55 sec continuing smoothly and increasing slowly until ~T+100 sec when the main emission started. The main peak is at T+120 sec. Smaller overlapping peaks continue out past T+550 sec. In particular, there is a small peak from T+730 to T+850 sec which is coincident with a peak (flare) in the XRT lightcurve (Fig 2, GCN Report 66.1, Starling et al.). T90 (15-350 keV) is 402 +- 10 sec (estimated error including systematics).