TITLE: GCN CIRCULAR NUMBER: 19338 SUBJECT: GRB 160424A: Swift-BAT refined analysis DATE: 16/04/24 20:17:34 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-61 to T+243 sec from the recent telemetry downlinks, we report further analysis of BAT GRB 160424A (trigger #683906) (Lien, et al., GCN Circ. 19335). The BAT ground-calculated position is RA, Dec = 319.482, -60.408 deg, which is RA(J2000) = 21h 17m 55.7s Dec(J2000) = -60d 24' 29.8" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 33%. The mask-weighted light curve shows a FRED-like peak starting at ~T-0.5 sec, peaking at ~T+0.4 sec, and ending at ~T+10 sec. T90 (15-350 keV) is 6.3 +- 1.0 sec (estimated error including systematics). The time-averaged spectrum from T-1.51 to T+6.63 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.40 +- 0.10. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.06 sec in the 15-150 keV band is 5.1 +- 0.4 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/683906/BA/