GCN Circular 39030

Jacob Smith (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

At 22:41:06.30 UT on 19 January 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250119C (trigger 759019271/250119945).
which was also detected by Swift/BAT-GUANO (Ronchini, S. et al. 2025, GCN 39008
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 ).
The Fermi GBM on-ground location is consistent with the Swift/BAT-GUANO position.

The angle from the Fermi LAT boresight is 66 degrees.

The GBM light curve consists of a single short emission episode with a duration (T90)
of about 1 s (50-300 keV). The time-averaged spectrum
from T0-0.2 to T0+0.2 s is best fit by
a power law function with an exponential high-energy cutoff. The power law index is -0.63 +/- 0.2 and the cutoff energy,
parameterized as Epeak, is 1120 +/- 420 keV.

The event fluence (10-1000 keV) in this time interval is
(5.4 +/- 0.4)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.064 s in the 10-1000 keV band is 4.9 +/- 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/