TITLE: GCN CIRCULAR NUMBER: 6365 SUBJECT: GRB 070429B, Swift-BAT refined analysis DATE: 07/04/29 16:37:10 GMT FROM: Scott Barthelmy at NASA/GSFC J. Tueller (GSFC), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU) on behalf of the Swift-BAT team: Using the data set from T-240 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 070429 (trigger #277582) (Markwardt, et al., GCN Circ. 6358). The BAT ground-calculated position is RA, Dec = 328.006, -38.857 deg which is RA(J2000) = 21h 52m 1.4s Dec(J2000) = -38d 51' 24.8" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 66%. The mask-weighted lightcurve shows 3 or 4 overlapping peaks starting at ~T-0.2s sec and ending at ~T+0.5 sec. T90 (15-350 keV) is 0.5 +- 0.1 sec (estimated error including systematics). The time-averaged spectrum from T-0.2 to T+0.3 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.71 +- 0.23. The fluence in the 15-150 keV band is 6.3 +- 1.0 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.45 sec in the 15-150 keV band is 1.8 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.