{
  "bibcode": "2008GCN..8297....1F",
  "body": "E. Fenimore (LANL), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),\nJ. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),\nC. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),\nT. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),\nJ. Tueller (GSFC), T. Ukwatta (GWU)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-239 to T+494 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 080928 (trigger #326115)\n(Sakamoto, et al., GCN Circ. 8292).  The BAT ground-calculated position is\nRA, Dec = 95.061, -55.176 deg, which is \n   RA(J2000)  =  06h 20m 14.6s \n   Dec(J2000) = -55d 10' 34.8\" \nwith an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 84%.\n \nWith all the data downlinked, the mask-weighted light curve shows\nthat BAT triggered on a weak blip that occurred long before the\nmain emission of this burst.  The initial peak started at ~T-10 sec,\npeaked at ~T_zero, and returned to baseline around T+30 sec.\nThen a second, slightly larger peak, started at ~T+50 and ended at ~T+130 sec.\nThen the main emission started at ~T+170, with a pair of peaks at ~T+205 and\n~T+215 sec.  The emaission tails down to almost background at T+400 sec\nat which time Swift started to enter the SAA and the errors on the flux\nbecome large.  T90 (15-350 keV) is 280 +- 30 sec (estimated error\nincluding systematics).\n \nThe time-averaged spectrum from T+51.1 to T+381.5 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.77 +- 0.12.  The fluence in the 15-150 keV band is 2.5 +- 0.2 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T+202.83 sec in the 15-150 keV band\nis 2.1 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence\nlevel. \n \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/326115/BA/",
  "circularId": 8297,
  "createdOn": 1222692092000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 080928, Swift-BAT final refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 080928"
}