TITLE:   GCN CIRCULAR
NUMBER:  32133
SUBJECT: GRB 220527A: Fermi GBM Observation
DATE:    22/05/27 18:13:27 GMT
FROM:    Joe Mangan at UCD  <joseph.mangan@ucdconnect.ie>

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)
and AGILE (Ursi et al 2022, GCN 32129). The Fermi GBM Final Real-time
Localization
(GCN 32130) 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/"