{
  "bibcode": "2015GCN.17806....1R",
  "body": "J. L. Racusin (NASA/GSFC), M. Axelsson (KTH), M. Yassine (LUPM), D. Kocevski (NASA/GSFC) \nreport on behalf of the Fermi-LAT team:\n\nAdditional data on GRB 150510A has been downlinked from Fermi and processed, and we report \nan improved LAT localization of \n\nR.A., Dec = 16.16,  4.79 (J2000)\n\nwith an error radius of 0.36 deg (90% containment, statistical error only).  This was 55 deg from the \nLAT boresight at the time of the trigger.  The GRB position was within the LAT FoV from ~500 s prior \nto the trigger to ~T0+600 s, when an autonomous repoint request to the initial GBM flight position \ncaused the spacecraft to slew away.\n\nThere are 13 photons with energies >100 MeV within a 12 degree radius around the GRB position. \nThe highest energy photon is detected at T0+170 s with an energy of 1.5 GeV.  The burst is also \ndetected in the LAT Low Energy (LLE) data with energies >30 MeV with a significance of 9 sigma \nabove background with a duration of ~20 s, coinciding with the time of the GBM emission.\n\nThe GRB localization is within the Swift Sun avoidance constraint, and will not emerge until May 25, \ntherefore a Swift TOO is not being requested.\n\nThe Fermi-LAT point of contact for this burst is Judith Racusin (judith.racusin@nasa.gov).\n\nThe Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to \ngreater than 300 GeV. It is the product of an international collaboration between NASA and DOE in \nthe U.S. and many scientific institutions across France, Italy, Japan and Sweden.",
  "circularId": 17806,
  "createdOn": 1431263608000,
  "email": "judith.racusin@nasa.gov",
  "subject": "GRB 150510A: Fermi-LAT Refined Analysis",
  "submitter": "Judith Racusin at GSFC  <judith.racusin@nasa.gov>",
  "eventId": "GRB 150510A"
}