TITLE:   GCN CIRCULAR
NUMBER:  31580
SUBJECT: GRB 220210A: Fermi GBM detection
DATE:    22/02/11 20:51:36 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

C. Malacaria (USRA), P. Veres (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 23:56:38.37 UT on 10 February 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220210A (trigger 666230203 / 220210998),
which was also detected by the Swift/BAT-GUANO (Tohuvavohu et al. 2022, GCN 31572),
Fermi-LAT (Longo et al. 2022, GCN 31576), and AGILE (Ursi et al. 2022, GCN 31575).
The Fermi GBM Final Real-time Localization (GCN 31568) 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 a main peak followed by fainter peaks
with a duration (T90) of about 43 s (10-1000 keV).
The time-averaged spectrum from T0-0.4 s to T0+2.7 s is
best fit by a power-law function with an exponential high-energy cutoff.
The power law index is -0.95 +/- 0.07 and the cutoff energy,
parameterized as Epeak, is 3530 +/- 986 keV.

The event fluence (10-1000 keV) in this time interval is
(4.9 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.192 s in the 10-1000 keV band
is 4.1 +/- 0.2 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/"