GCN Circular 29328

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


At 02:54:09.82 UT on 19 January 2021, the Fermi Gamma-Ray Burst
Monitor (GBM) triggered and located GRB 210119A (trigger 632717654 /
210119.121),
which was also detected by the Swift/BAT (M. J. Moss et al. 2021, GCN
29323
Not found
 
 
). The Fermi GBM Final Real-time Localization (GCN 29322
Not found
 
 
) is
consistent with the Swift position.


The angle from the Fermi LAT boresight at the GBM trigger time is 8 deg degrees.

The GBM light curve consists of a short bright burst
with a duration (T90) of about 0.05 s (50-300 keV).
The time-averaged spectrum from T0-0.064 s to T0+0.064 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.82 +/- 0.18 and
the cutoff energy, parameterized as Epeak, is 515 +/- 168 keV.
Unlikely to be an SGR given Epeak result. The event fluence (10-1000
keV) in this time interval is
(3.432 +/- 0.397)E-7 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.064 s in the 10-1000 keV band
is 11.7 +/- 1.3 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.htmlFor Fermi
GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"