{
  "bibcode": "2009GCN.10051....1P",
  "body": "D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),\nJ. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),\nH. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), A. M. Parsons (GSFC),\nJ. L. Racusin (NASA/GSFC/ORAU), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),\nM. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)\n(i.e. the Swift-BAT team):\n\nUsing the data set from T-61 to T+242 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 091020 (trigger #373458)\n(Racusin, et al., GCN Circ. 10048).  The BAT ground-calculated position is\nRA, Dec = 175.727, 50.977 deg which is\n    RA(J2000)  =  11h 42m 54.4s\n    Dec(J2000) = +50d 58' 36.6\"\nwith an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 43%.\n\nThe mask-weighted light curve began with a small hump at T-10 sec, rising\nsharply to a peak at T+2 sec and decaying exponentially out to T+50 sec,\nwith a much smaller peak superimposed at T+30 sec. T90 (15-350 keV) is\n34.6 +- 2.7 sec (estimated error including systematics).\n\nThe time-averaged spectrum from T-8.7 to T+38.3 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.53 +- 0.07.  The fluence in the 15-150 keV band is\n3.7 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from\nT+1.14 sec in the 15-150 keV band is 4.2 +- 0.3 ph/cm2/sec.  All the\nquoted errors are at the 90% confidence level.\n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/373458/BA/",
  "circularId": 10051,
  "createdOn": 1256088539000,
  "email": "hans.krimm@nasa.gov",
  "subject": "GRB 091020, Swift-BAT refined analysis",
  "submitter": "Hans Krimm at NASA-GSFC  <hans.krimm@nasa.gov>",
  "eventId": "GRB 091020"
}