TITLE: GCN CIRCULAR NUMBER: 23980 SUBJECT: GRB 190320A: Swift-BAT refined analysis DATE: 19/03/20 11:41:19 GMT FROM: Hans Krimm at NSF/NASA-GSFC H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), J.D. Gropp (PSU), 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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190320A (trigger #893808) (Gropp, et al., GCN Circ.23973). The BAT ground-calculated position is RA, Dec = 117.824, -45.876 deg which is RA(J2000) = 07h 51m 17.8s Dec(J2000) = -45d 52' 33.3" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 29%. The mask-weighted light curve shows a single episode with some superimposed structure from roughly T-25 to T+40 sec. The spacecraft slewed away from the burst position at around T+500 sec. T90 (15-350 keV) is 64.0 +- 12.1 sec (estimated error including systematics). The time-averaged spectrum from T-27.20 to T+44.80 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.20 +- 0.20. The fluence in the 15-150 keV band is 2.7 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.20 sec in the 15-150 keV band is 1.3 +- 0.5 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/893808/BA/