{
  "bibcode": "2017GCN.21157....1S",
  "body": "M. Stanbro (UAH), C. M. Hui (NASA/MSFC), C. Meegan (UAH)\nand A. von Kienlin (MPE) report on behalf of the Fermi GBM Team:\n\nAt 11:31:02.37 UT on 27 May 2017, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 170527A (trigger 517577467 / 170527480).\n\nThe on-ground calculated location, using the GBM trigger\ndata, is RA = 195.19 , DEC = +0.94  (J2000 degrees,\nequivalent to 13h 00m, +0d 54.0'), with an uncertainty\nof 1.00 degrees (radius, 1-sigma containment, statistical only; \nthere is additionally a systematic error which we have characterized \nas a core-plus-tail model, with 90% of GRBs having a 3.7 deg error \nand a small tail suffering a larger than 10 deg systematic error \n[Connaughton et al. 2015, ApJS, 216, 32] ).\n\nThe trigger resulted in an Autonomous Repoint Request (ARR)\nby the GBM Flight Software owing to the high peak flux of the GRB.\nThis ARR was accepted and the spacecraft slewed \nto the GBM in-flight location. The initial angle from the \nFermi LAT boresight is 37.00 degrees.\n\nThe GBM light curve shows a sharp peak with multiple sub-structures\nwith a duration (T90) of about 49.2 s (50-300 keV).\nThe time-averaged spectrum from T0+1.1 s to T0+50.3 s is \nadequately fit by a power law function with an exponential\nhigh-energy cutoff.  The power law index is -1.03 +/- 0.01 and\nthe cutoff energy, parameterized as Epeak, is 1001.00 +/- 33.50 keV\n\nThe event fluence (10-1000 keV) in this time interval is\n(8.430 +/- 0.003)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+0.8 s in the 10-1000 keV band is \n22.19 +/- 0.36 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.",
  "circularId": 21157,
  "createdOn": 1495915797000,
  "email": "c.m.hui@nasa.gov",
  "subject": "GRB 170527A: Fermi GBM detection",
  "submitter": "C. Michelle Hui at MSFC/Fermi-GBM  <c.m.hui@nasa.gov>",
  "eventId": "GRB 170527A"
}