{
  "bibcode": "2021GCN.31210....1M",
  "body": "J.Mangan (UCD), R.Dunwoody (UCD) and C.Meegan (UAH)\nreport on behalf of the Fermi GBM Team:\n\nAt 13:09:59.651 UT on 11 December 2021, the Fermi Gamma-Ray Burst Monitor (GBM)\ntriggered and located GRB 211211A (trigger 660921004 / 211211549)\nwhich was also detected by the Swift/BAT (D'Ai et al., GCN 31202). The\nFermi GBM Final Real-time Localization (GCN 31201) is consistent with\nthe Swift position.\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 106.5 degrees.\n\nThe GBM light curve consists of an exceptionally bright emission made\nup of three separate pulses\nwith a duration (T90) of about 34.3s (50-300 keV).\nThe time-averaged spectrum from T0-1.264 s to T0+54.033 s is\nbest fit by a Band function with Epeak = 646.8 +/- 7.8 keV,\nalpha = -1.3 +/- 0.00, and beta = -2.4 +/- 0.02\n\nThe event fluence (10-1000 keV) in this time interval is\n(5.4 +/- 0.01)E-04 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+6.8 s in the 10-1000 keV band\nis 324.9 +/- 1.5 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB\nCatalog:https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n\nFor Fermi GBM data and info, please visit the official Fermi GBM\nSupport Page:https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/",
  "circularId": 31210,
  "createdOn": 1639294296000,
  "email": "joseph.mangan@ucdconnect.ie",
  "subject": "GRB 211211A: Fermi GBM observation",
  "submitter": "Joe Mangan at UCD  <joseph.mangan@ucdconnect.ie>",
  "eventId": "GRB 211211A"
}