TITLE: GCN CIRCULAR NUMBER: 9406 SUBJECT: GRB 090519, Swift-BAT refined analysis DATE: 09/05/20 02:30:23 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), M. Perri (ASDC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-119 to T+276 sec from the recent telemetry downlink, we report further analysis of BAT GRB 090519 (trigger #352648) (Perri, et al., GCN Circ. 9400). The BAT ground-calculated position is RA, Dec = 142.317, 0.190 deg which is RA(J2000) = 09h 29m 16.2s Dec(J2000) = +00d 11' 23.9" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). This is 0.8 arcmin from the enhanced XRT afterglow position (Goad et al. GCN Circ #9405). The partial coding was 57%. The mask-weighted lightcurve shows multiple overlapping peaks starting at about T-17 sec and ending about T+95 sec. T90 (15-350 keV) is 64 +- 10 sec (estimated error including systematics). The time-averaged spectrum from T-12.4 to T+60.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.02 +- 0.20. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10-06 erg/cm2. The 1-sec peak photon flux measured from T-10 sec in the 15-150 keV band is 0.6 +- 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/352648/BA/