GCN Circular 32133

J. Mangan (UCD), R. Dunwoody (UCD), and C.Meegan (UAH)
report on behalf of the Fermi GBM Team:

At 09:17:15.73 UT on 27 May 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220527A (trigger 675335840 / 220527387),
which was also detected by the Fermi LAT (Bissaldi et al. 2022, GCN 32131
Not found
 
 
)
and AGILE (Ursi et al 2022, GCN 32129
Not found
 
 
). The Fermi GBM Final Real-time
Localization
(GCN 32130
Not found
 
 
) is consistent with the Fermi LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 49
degrees.

The GBM light curve consists of a double peak emission
with a duration (T90) of about 10.5 s (50-300 keV).
The time-averaged spectrum from T0-0.13 s to T0+21.38 s is best fit by
a Band function with Epeak = 151.6 +/- 2.7 keV,
alpha = -0.75 +/- 0.02, and beta = -2.55 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(5.69 +/- 0.04)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.4 s in the 10-1000 keV band
is 92.6 +/- 0.7 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/"