TITLE: GCN CIRCULAR NUMBER: 21018 SUBJECT: GRB 170419A: Swift-BAT refined analysis DATE: 17/04/20 01:00:29 GMT FROM: Amy Lien at GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-190 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170419A (trigger #748898) (Sbarufatti et al., GCN Circ. 21013). The BAT ground-calculated position is RA, Dec = 79.854, -21.433 deg which is RA(J2000) = 05h 19m 25.1s Dec(J2000) = -21d 25' 58.0" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%. The mask-weighted light curve shows a single-pulse structure that starts and peaks at ~T0. The main emission ends at ~T+3 s, with a tail that lasts till ~T+9 s. T90 (15-350 keV) is 8.18 +- 2.00 sec (estimated error including systematics). The time-averaged spectrum from T-0.39 to T+8.92 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.06 +- 0.26. The fluence in the 15-150 keV band is 3.1 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.47 sec in the 15-150 keV band is 1.5 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/748898/BA/