{
  "submitter": "Lorenzo Scotton at UAH <lscottongcn@outlook.com>",
  "bibcode": "2023GCN.34392....1S",
  "circularId": 34392,
  "createdOn": 1691895020385,
  "submittedHow": "web",
  "eventId": "GRB 230812B",
  "body": "L. Scotton (UAH), D. Kocevski (NASA/MSFC), J. Racusin (NASA/GSFC), and N. Omodei (Stanford University)\nreport on behalf of the Fermi-LAT Collaboration:\n\nOn August 12, 2023, Fermi-LAT detected high-energy emission from\nGRB 230812B, which was also detected by Fermi-GBM (trigger 713559497/230812790, S. Lesage GCN 34387, O. Roberts GCN 34391).\n\nThe best LAT on-ground location is found to be\n\nRA, Dec = 249.10, 47.75 (degrees, J2000)\n\nwith an error radius of 0.13 deg (90% containment, statistical error only).\nThis was 29 deg from the LAT boresight at the time of the GBM trigger:\n\nT0 = 18:58:12.05 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 the\nGBM emission (1.69 degrees from the GBM location) with high significance.\nThe photon flux above 100 MeV in the time interval 0-50 s after the\nGBM trigger is (1.96 +/- 0.27)E-4 ph/cm2/s.\n\nThe estimated photon index above 100 MeV is -2.16 +/- 0.14.\n\nThe highest-energy photon is a 72 GeV event which is observed 32.2 seconds\nafter the GBM trigger.\n\nThe Fermi-LAT point of contact for this burst is\nLorenzo Scotton (lorenzo.scotton AT uah.edu).\n\nThe Fermi-LAT is a pair conversion telescope designed to cover\nthe energy band from 20 MeV to greater than 300 GeV.\nIt is the product of an international collaboration between\nNASA and DOE in the U.S. and many scientific institutions\nacross France, Italy, Japan and Sweden.",
  "subject": "GRB 230812B: Fermi-LAT detection"
}