{
  "bibcode": "2017GCN.22066....1L",
  "body": "A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),\nJ. R. Cummings (CPI), P. D'Avanzo (INAF-OAB),\nH. A. Krimm (NSF/USRA), C. B. Markwardt (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-61 to T+243 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 171027A (trigger #783479)\n(D'Avanzo et al., GCN Circ. 22053).  The BAT ground-calculated position is\nRA, Dec = 61.683, -2.601 deg which is\n  RA(J2000)  =  04h 06m 43.8s\n  Dec(J2000) = -02d 36' 02.0\"\nwith an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 91%.\n\nThe mask-weighted light curve shows a multi-peaked structure that starts\nat ~T-2 s and ends at ~T+150 s. The main peak occurs at ~ T+63 s.\nT90 (15-350 keV) is 96.6 +- 4.8 sec (estimated error including systematics).\n\nThe time-averaged spectrum from T-2.0 to T+132.0 sec is best fit by a power law\nwith an exponential cutoff.  This fit gives a photon index 1.25 +- 0.18,\nand Epeak of 150.4 +- 95.1 keV (chi squared 33.21 for 56 d.o.f.).  For this\nmodel the total fluence in the 15-150 keV band is 7.5 +- 0.2 x 10^-6 erg/cm2\nand the 1-sec peak flux measured from T+62.29 sec in the 15-150 keV band is\n3.0 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index\nof 1.53 +- 0.04 (chi squared 40.62 for 57 d.o.f.).  All the quoted errors\nare at the 90% confidence level.\n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/783479/BA/",
  "circularId": 22066,
  "createdOn": 1509207767000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "GRB 171027A, Swift-BAT refined analysis",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "GRB 171027A"
}