GCN Circular 35549

R. Hamburg (CNRS/IN2P3), S. Bala (USRA), and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 16:45:37.62 UT on 15 January 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240115B (trigger 727029942/240115698). GRB 240115B
was also localized by INTEGRAL (S. Mereghetti et al. 2024, GCN 35541
Not found
 
 
).

The angle from the Fermi LAT boresight is 97 degrees.

The GBM light curve consists of multiple peaks of emission
with a duration (T90) of about 163 s (50-300 keV). 
The time-averaged spectrum from T0-26.63 s to T0+47.11 s 
is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.73 +/- 0.11,
and the cutoff energy parameterized as Epeak, is 125 +/- 10.

The event fluence (10-1000 keV) in this time interval is
(5.13 +/- 0.26)E-06 erg/cm^2. The 1-sec peak photon flux measured
 starting from T0+17.6 s in the 10-1000 keV band is 2.6 +/- 0.3 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.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"