TITLE: GCN CIRCULAR NUMBER: 5678 SUBJECT: GRB 061002, Swift-BAT refined analysis DATE: 06/10/02 04:03:31 GMT FROM: Scott Barthelmy at NASA/GSFC D. Hullinger (BYU-Idaho), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC), 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), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the data set from T-239 to T+303 sec from the recent telemetry downlink, we report further analysis of BAT GRB 061002 (trigger #231974) (Cannizzo, et al., GCN Circ. 5676). The BAT ground-calculated position is RA,Dec = 220.356, 48.726 deg {14h 41m 25.4s, 48d 43' 32.0"} (J2000) +- 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 39%. The mask-weighted lightcurve has a single roughly triangular shaped peak starting at T-10 sec, peaking at T+10 sec, and ending at T+60 sec. There is one caveate to this in that there is a 20-sec gap in the downliked data starting at T+160 sec. T90 (15-350 keV) is 17.6 +- 1 sec (estimated error including systematics). The time-averaged spectrum from T-2.3 to T+16.9 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.76 +- 0.21. The fluence in the 15-150 keV band is 6.8 +- 0.8 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-1.38 sec in the 15-150 keV band is 0.8 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.