TITLE:   GCN CIRCULAR
NUMBER:  29073
SUBJECT: GRB 201216C: Fermi GBM detection
DATE:    20/12/17 15:03:27 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

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

"At 23:07:25.75 UT on 16 December 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201216C (trigger 629852850 / 201216963),
which was also detected by the Swift/BAT (Beardmore et al. 2020, GCN 29061).
The Fermi GBM Final Real-time Localization (GCN 29063) is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 94 degrees.

GRB 201216C is particularly bright and hard.
The GBM light curve shows a broad, structured peak
with a duration (T90) of about 29.9 s (50-300 keV).
The time-averaged spectrum from T0-0.003 s to T0+49.665 s is
best fit by a Band function with Epeak = 326 +/- 7  keV,
alpha = -1.06 +/- 0.01, and beta = -2.25 +/- 0.03.

The event fluence (10-1000 keV) in this time interval is
(1.41 +/- 0.06)E-4 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+24.8 s in the 10-1000 keV band
is 54.9 +/- 0.6 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/"