{
  "bibcode": "2018GCN.23597....1D",
  "body": "F. Dirirsa (U. Johannesburg) and M. Ohno (Hiroshima U.)\nreport on behalf of the Fermi-LAT team:\n\nOn December, 31, 2018 Fermi-LAT detected high-energy emission from GRB\n181231A, which was also detected by Fermi-GBM (trigger 567919668 /\n181231144).\n\nThe best LAT on-ground location is found to be\n\nRA, Dec = 254.59, 0.61 (degrees, J2000)\n\nwith an error radius of 0.24 deg (90 % containment, statistical error\nonly).\nThis was 51 deg from the LAT boresight at the time of the GBM trigger:\n\nT0 =  03:27:43.8 UT.\n\nThe data from the Fermi-LAT show a significant increase\nin the event rate after the GBM trigger that is spatially correlated with\nthe\nGBM emission (7.8 degrees from the GBM location) with high significance.\nThe photon flux above 100 MeV in the time interval 0-5000 s after the\nGBM trigger is 2.4 (+/-1.2)E-6 ph/cm2/s.\nThe estimated photon index above 100 MeV is 2.21 (+/-0.37).\n\nA Swift ToO has been requested for this burst\n\nThe Fermi-LAT point of contact for this burst is Feraol F. Dirirsa (\nfdirirsa@uj.ac.za).\n\nThe Fermi-LAT is a pair conversion telescope designed to cover the energy\nband from 20 MeV to greater than 300 GeV. It is the product of an\ninternational collaboration between NASA and DOE in the U.S. and many\nscientific institutions across France, Italy, Japan and Sweden.",
  "circularId": 23597,
  "createdOn": 1546278929000,
  "email": "ohno@astro.hiroshima-u.ac.jp",
  "subject": "GRB 181231A: Fermi-LAT detection",
  "submitter": "Masanori Ohno at Hiroshima University  <ohno@astro.hiroshima-u.ac.jp>",
  "eventId": "GRB 181231A"
}