{
  "bibcode": "2021GCN.30585....1R",
  "body": "O.J.Roberts (USRA/NASA-MSFC) and C.Meegan (UAH)\nreport on behalf of the Fermi GBM Team:\n\n\"At 13:57:18.60 UT on 01 August 2021, the Fermi Gamma-Ray Burst Monitor (GBM)\ntriggered and located GRB 210801A (trigger 649519043 / 210801581).\n\nThe on-ground calculated location, using the GBM trigger data, is \nRA = 252.77, DEC = -45.82 (J2000 degrees, \nequivalent to 16 h 51 m, -45 d 49 '), with a statistical uncertainty\nof 1.6 degrees (radius, 1-sigma containment, statistical only; there is \nadditionally a systematic error which we have characterized as a \ncore-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small \ntail suffering a larger than 10 deg systematic error. \n[Connaughton et al. 2015, ApJS, 216, 32] ).\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 120 degrees.\n\nThe GBM light curve shows two pulses (the second is much brighter than the \nfirst), with a duration (T90) of about 14 s (50-300 keV). The time-averaged \nspectrum from T0-0.2 s to T0+13.4 s is best fit by a Band function with \nEpeak = 41.8 +/- 1.5 keV, alpha = -1.51 +/- 0.05, and beta = -2.98 +/- 0.3.\n\nA power law function with an exponential high-energy cutoff fits the spectrum \nequally well with a power law index of -1.56 +/- 0.04 and a cutoff energy, \nparameterized as Epeak, of 43.0 +/- 1.5 keV\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.44 +/- 0.04)E-05  erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+10.3 s in the 10-1000 keV band is 70 +/- 1 ph/s/cm^2.\n\nWe note that the position of this burst lies along the galactic plane.\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": 30585,
  "createdOn": 1627919601000,
  "email": "oliver.roberts@nasa.gov",
  "subject": "GRB 210801A: Fermi GBM detection",
  "submitter": "Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>",
  "eventId": "GRB 210801A"
}