TITLE: GCN CIRCULAR NUMBER: 13450 SUBJECT: GRB 120711B: Swift-BAT refined analysis DATE: 12/07/11 22:05:20 GMT FROM: Scott Barthelmy at NASA/GSFC T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), M. J. Page (UCL-MSSL), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC) (i.e. the Swift-BAT team): Using the data set from T-141 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120711B (trigger #526270) (Page, et al., GCN Circ. 13431). The BAT ground-calculated position is RA, Dec = 331.710, 59.996 deg, which is RA(J2000) = 22h 06m 50.5s Dec(J2000) = +59d 59' 46.0" with an uncertainty of 3.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 80%. The mask-weighted light curve shows the emission starting ~T-100 sec, peaking at ~T+20 sec, and slowly decaying out to T+875 sec. T90 (15-350 keV) is 60 +- 19 sec (estimated error including systematics). The time-averaged spectrum from T-12.1 to T+51.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.75 +- 0.32. The fluence in the 15-150 keV band is 5.6 +- 1.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+13.11 sec in the 15-150 keV band is 0.4 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. Contrary to our GCN 13431, we now think that this trigger is very likely GRB, and not a new Galactic source. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/526270/BA/