TITLE: GCN CIRCULAR NUMBER: 10221 SUBJECT: GRB 091130B: Swift-BAT refined analysis DATE: 09/12/01 05:44:50 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift T. N. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), 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), A. M. Parsons (GSFC), J. L. Racusin (NASA/GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 091130B (trigger #377487) (Racusin, et al., GCN Circ. 10214). The BAT ground-calculated position is RA, Dec = 203.149, 34.086 deg which is RA(J2000) = 13h 32m 35.8s Dec(J2000) = +34d 05' 11.0" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%. The mask-weighted light curve shows several broad, irregular, overlapping peaks starting at T-25 sec, peaking at T0 and ending about T+120 sec. T90 (15-350 keV) is 112.5 +- 17.1 sec (estimated error including systematics). The time-averaged spectrum from T-4.7 to T+127.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.15 +- 0.15. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band is 1.1 +- 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/377487/BA/ [GCN OPS NOTE(01dec09): Changed "091130" to "091130B".]