TITLE:   GCN CIRCULAR
NUMBER:  29072
SUBJECT: GRB 201216A: Fermi GBM detection
DATE:    20/12/17 15:01:51 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

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

"At 19:00:31.24 UT on 16 December 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201216A (trigger 629838036 / 201216792),
which was also detected by the Swift/BAT (Tohuvavohu et al. 2020, GCN 29059)
and initiated a Swift/XRT ToO (Evans 2020, GCN 29065).
The Fermi GBM Final Real-time Localization (GCN 29057) is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 30 degrees.

The GBM light curve consists of a main peak followed by multiple subsequent peaks.
The duration (T90) is about 25.6 s (50-300 keV).
The time-averaged spectrum from T0-10 s to T0+13 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.51 +/- 0.22 and
the cutoff energy, parameterized as Epeak, is 263 +/- 55 keV.

The event fluence (10-1000 keV) in this time interval is
(2.343 +/- 0.330)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+64 ms in the 10-1000 keV band
is 1.6 +/- 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/"