{
  "bibcode": "2015GCN.18788....1V",
  "body": "P Veres (UAH) and C Meegan (UAH)\nreport on behalf of the Fermi GBM Team:\n\n\"At 13:38:08.17 UT on 31 December 2015, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 151231B (trigger 473261892 / 151231568).\n\n\nThe on-ground calculated location, using the GBM trigger\ndata, is RA = 150.1, DEC = 28.8 (J2000 degrees,\nequivalent to 10 h 0 m, 28 d 49 '), with an uncertainty\nof 3.1 degrees (radius, 1-sigma containment,\nstatistical only; there is additionally a systematic\nerror which we have characterized as a core-plus-tail model, with 90% of\nGRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg\nsystematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 50 degrees.\n\nThe GBM light curve consists of a single pulse\nwith a duration (T90) of about 0.8 s (50-300 keV).\nThe time-averaged spectrum from T0-0.3 s to T0+0.4 s is\nabest fit by a power law function with an exponential\nhigh-energy cutoff.  The power law index is -0.65 +/- 0.10 and\nthe cutoff energy, parameterized as Epeak, is 419 +/- 58 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.20 +/- 0.07)E-6 erg/cm^2. The 64 ms peak photon flux measured\nstarting from T0 in the 10-1000 keV band is 14.8 +/- 1.2 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 18788,
  "createdOn": 1451590926000,
  "email": "veresp@gmail.com",
  "subject": "GRB 151231B: Fermi GBM observation",
  "submitter": "Peter Veres at UAH  <veresp@gmail.com>",
  "eventId": "GRB 151231B"
}