TITLE: GCN CIRCULAR NUMBER: 25211 SUBJECT: GRB 190727B: Swift-BAT refined analysis DATE: 19/07/28 23:21:40 GMT FROM: Amy Lien at GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), 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 190727B (trigger #916733) (Lien et al., GCN Circ. 25176). The BAT ground-calculated position is RA, Dec = 126.500, -13.272 deg which is RA(J2000) = 08h 25m 59.9s Dec(J2000) = -13d 16' 18.9" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 70%. The mask-weighted light curve shows a structure with multiple bright pulses that starts at ~T-20 s and ends at ~T+45 s. The brightest peak occurs at ~T+2 s. T90 (15-350 keV) is 40.14 +- 1.40 sec (estimated error including systematics). The time-averaged spectrum from T-21.30 to T+44.47 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.41 +- 0.03. The fluence in the 15-150 keV band is 1.8 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+1.13 sec in the 15-150 keV band is 20.9 +- 0.7 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/916733/BA/