TITLE: GCN CIRCULAR NUMBER: 5732 SUBJECT: GRB 061019, Swift-BAT refined analysis DATE: 06/10/19 15:50:14 GMT FROM: Scott Barthelmy at NASA/GSFC T. Sakamoto (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), C. Guidorzi (Univ Bicocca&INAF-OAB), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) 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 061019 (trigger #234516) (Guidorzi, et al., GCN Circ. 5728). The BAT ground-calculated position (using the second peak only) is RA,Dec = 91.631, 29.545 deg {6h 6m 31.5s, 29d 32' 43.3"} (J2000) +- 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 5%. The mask-weighted lightcurve shows two peaks. The first (pre-trigger peak), started ~T-170 sec and lasted for ~20 sec. The second peak (the triggering peak) rises a little faster than decaying. It starts at ~T-4 sec, peaks at T+4 sec, and ends at ~T+30 sec. The second peak is a little brighter than the first. There is a hint of on-going emission between the two peaks. Because of a s/c slew terminating the data collection, we can not say if there is any further emission past T+60 sec. T90 is 191 +- 3 sec (estimated error including systematics). For the second (triggering peak), the time-averaged spectrum from T-4.0 to T+27.7 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.85 +- 0.26. The fluence in the 15-150 keV band is 1.7 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+3.57 sec in the 15-150 keV band is 2.2 +- 0.6 ph/cm2/sec. For the first (pre-trigger peak), the time-averaged spectrum from T-175 to T-150 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.17 +- 0.40. The fluence in the 15-150 keV band is 7.3 +- 1.9 x 10^-7 erg/cm2. The total fluence (both peaks) is 2.4 +- 0.3 x 10^-6 srg/cm2. All the quoted errors for both fits are at the 90% confidence level.