TITLE:   GCN CIRCULAR
NUMBER:  27841
SUBJECT: GRB 200528A: Fermi GBM Observation
DATE:    20/05/28 23:28:45 GMT
FROM:    Cori Fletcher at USRA  <cfletcher@usra.edu>

C. Fletcher (USRA), A. von Kienlin and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 10:27:24.35 UT on 28 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 200528A (trigger 612354449 / 200528436)
which was also detected by the Swift/BAT (Ambrosi et al. 2020, GCN 27832)
The Fermi GBM Final Real-time Localization (GCN 27831) is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 16 degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 56 s (50-300 keV).
The time-averaged spectrum from T0+2.05 s to T0+59.4 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.39 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 55.5 +/- 0.8 keV.

The event fluence (10-1000 keV) in this time interval is
(2.54 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+33.3 s in the 10-1000 keV band
is 27.2 +/- 0.4 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/"