{
  "bibcode": "2018GCN.23569....1B",
  "body": "E. Bissaldi (Politecnico & INFN Bari) and P. Veres (UAH)\nreport on behalf of the Fermi GBM Team:\n\n\"At 06:17:00.50 UT on 27 December 2018, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 181227A (trigger 567584225 / 181227262).\n\nThe on-ground calculated location, using the GBM trigger\ndata, is\n\nRA, Dec = 24.2, -56.1\n\n(J2000 degrees), with an uncertainty of 1 degree (radius, 1-sigma\ncontainment,\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 110\ndegrees.\n\nThe GBM light curve consists of two peaks\nwith a duration (T90) of about 13 s (50-300 keV).\nThe time-averaged spectrum from T0-0.3 s to T0+19.8 s is\nbest fit by a Band function with Epeak = 85 +/- 1 keV,\nalpha = -0.33 +/- 0.02, and beta = -3.08 +/- 0.05.\n\nThe event fluence (10-1000 keV) in this time interval is\n(6.85 +/- 0.05)E-5 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+8.9 s in the 10-1000 keV band\nis 110.5 +/- 1.2 ph/s/cm^2.\n\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\"\n\n[GCN OPS NOTE(27dec18):  Per author's request, the alpha value\nin the third paragraph was changed from \"0.33\" to \"-0.33\".]",
  "circularId": 23569,
  "createdOn": 1545948373000,
  "email": "veresp@gmail.com",
  "subject": "GRB 181227A: Fermi GBM detection",
  "submitter": "Peter Veres at UAH  <veresp@gmail.com>",
  "eventId": "GRB 181227A"
}