{
  "bibcode": "2007GCN..6643....1P",
  "body": "D. Palmer (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC),\nJ. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),\nH. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), A. Parsons (GSFC),\nT. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU),\nJ. Tueller (GSFC), T. Ukwatta (GWU), H. Ziaeepour (UCL-MSSL)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-119 to T+183 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 070721B (trigger #285654)\n(Ziaeepout, et al., GCN Circ. 6640).  The BAT ground-calculated position is\nRA, Dec = 33.128, -2.198 deg  which is \n   RA(J2000)  =  2h 12m 30.8s \n   Dec(J2000) = -2d 11' 54\" \nwith an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 23%.\n \nThe mask-weighted light curve shows a large main peak starting at ~T-20 sec,\npeaking at ~T+0 sec, and ending at ~T+70 sec.  We caution that currently\nwe only have downlinked data out to T+183 sec, and that there is a hint\nof activity past T+70 sec.  But we wanted to get this circular out without\nwaiting for further downlinks due to the uncertainites given the GCN Notices\nproblems earlier.  T90 (15-350 keV) is 31.5 +- TTT sec (estimated error\nincluding systematics).\n \nThe time-averaged spectrum from T-6.7 to T+33.7 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.31 +- 0.11.  The fluence in the 15-150 keV band is 2.1 +- 0.1 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T-0.14 sec in the 15-150 keV band\nis 1.5 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence\nlevel.",
  "circularId": 6643,
  "createdOn": 1185027737000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 070721B, Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 070721B"
}