{
  "subject": "GRB 171216A: Swift-BAT refined analysis",
  "eventId": "GRB 171216A",
  "bibcode": "2017GCN.22259....1M",
  "createdOn": 1513444132000,
  "circularId": 22259,
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "email": "amy.y.lien@nasa.gov",
  "body": "C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),\nJ. R. Cummings (CPI), H. A. Krimm (NSF/USRA),\nA. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),\nD. M. Palmer (LANL), T. Sakamoto (AGU),\nM. Stamatikos (OSU), T. N. Ukwatta (LANL)\n(i.e. the Swift-BAT team):\n\nUsing the data set from T-240 to T+302 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 171216A (trigger #797441)\n(Marshall et al., GCN Circ. 22256).  The BAT ground-calculated position is\nRA, Dec = 212.013, -50.500 deg which is\n  RA(J2000)  =  14h 08m 03.0s\n  Dec(J2000) = -50d 30' 01.2\"\nwith an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 63%.\n\nThe mask-weighted light curve shows a weak single-peaked structure that\nstarts at ~T0, peaks at ~T+3 s, and ends at ~ T+30 s. T90 (15-350 keV)\nis 30.0 +- 7.5 sec (estimated error including systematics).\n\nThe time-averaged spectrum from T-0.45 to T+33.47 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.63 +- 0.30.  The fluence in the 15-150 keV band is 4.8 +- 1.0 x 10^-7 erg/cm2.\nThe 1-sec peak photon flux measured from T+3.05 sec in the 15-150 keV band\nis 0.8 +- 0.2 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/797441/BA/"
}