TITLE: GCN CIRCULAR NUMBER: 27466 SUBJECT: GRB 200327A: Fermi GBM detection DATE: 20/03/29 01:40:48 GMT FROM: Peter Veres at UAH P. Veres and C. Meegan (both UAH) report on behalf of the Fermi GBM Team: "At 20:56:48.17 UT on 27 March 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200327A (trigger 607035413 / 200327873) which was also detected by AGILE-MCAL (Ursi et al., GCN 27461) and localized by IPN (Svinkin et al., GCN 27463). The GBM on-ground location is consistent with the IPN position. The angle from the Fermi LAT boresight at the GBM trigger time is 104 degrees. The GBM light curve consists of two pulses with a duration (T90) of about 0.64 s (50-300 keV). The time-averaged spectrum from T0-64 ms to T0+192 ms is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.60 +/- 0.09 and the cutoff energy, parameterized as Epeak, is 1100 +/- 180 keV. The event fluence (10-1000 keV) in this time interval is (1.53 +/- 0.06)E-6 erg/cm^2. The 64 ms peak photon flux measured starting from T0+64 ms in the 10-1000 keV band is 19.2 +/- 1.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"