{
  "bibcode": "2021GCN.30219....1F",
  "body": "C. Fletcher (USRA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:\n\n\"At 15:21:45.97 UT on 28 December 2020, the Fermi Gamma-Ray Burst Monitor (GBM)\ntriggered and located GRB 201228B (trigger 630861710 / 201228640)\nwhich was also detected by the Swift/BAT-GUANO (DeLaunay et al. 2021, GCN 29985)\nThe Fermi GBM Final Real-time Localization (GCN 29188) is consistent with the Swift position.\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 39 degrees.\n\nThe GBM light curve consists of single peak with a duration (T90) of about 30 s (50-300 keV).\nThe time-averaged spectrum from T0-1.5 to T0+30.2 s is best fit by a Band function with\nEpeak = 49 +/- 14 keV, alpha = 0.8 +/- 1.2, and beta = -1.9 +/- 0.1.\n\nThe event fluence (10-1000 keV) in this time interval is (2.199 +/- 0.251)E-06 erg/cm^2.\nThe 1-sec peak photon flux measured starting from T0+1.8 s in the 10-1000 keV band\nis 1.3 +/- 0.2 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog:\nhttps://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n\nFor Fermi GBM data and info, please visit the official Fermi GBM Support Page:\nhttps://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "circularId": 30219,
  "createdOn": 1623456792000,
  "email": "cfletcher@usra.edu",
  "subject": "GRB 201228B: Fermi GBM observation",
  "submitter": "Cori Fletcher at USRA  <cfletcher@usra.edu>",
  "eventId": "GRB 201228B"
}