TITLE: GCN CIRCULAR NUMBER: 9384 SUBJECT: GRB 090516: Swift-BAT refined analysis DATE: 09/05/17 16:59:56 GMT FROM: Scott Barthelmy at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), B. A. Rowlinson (U Leicester), 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-240 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090516 (trigger #352190) (Rowlings, et al., GCN Circ. 9374). The BAT ground-calculated position is RA, Dec = 138.246, -11.848 deg, which is RA(J2000) = 09h 12m 59.1s Dec(J2000) = -11d 50' 51.4" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 9%. The mask-weighted light curve shows several overlapping peaks starting at ~T-20 sec witht he last peak at ~T+180 sec, and then decaying to background at ~T+330 sec. The burst went out of the BAT FOV at T+700 sec when Swift did a pre-programmed slew. T90 (15-350 keV) is 210 +- 65 sec (estimated error including systematics). The time-averaged spectrum from T-15.5 to T+288.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.84 +- 0.11. The fluence in the 15-150 keV band is 9.0 +- 0.6 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+7.98 sec in the 15-150 keV band is 1.6 +- 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/352190/BA/ [GCN OPS NOTE(17may09): Per author's request, the TBDs in the first sentence in the third paragraph were replaced with the actual times.]