TITLE:   GCN CIRCULAR
NUMBER:  45181
SUBJECT: GRB 260718A: Fermi GBM Observation
DATE:    26/07/18 17:24:01 GMT
FROM:    A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>

A. Holzmann Airasca (UniTrento and INFN Bari) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 11:16:35.01 UT on 18 July 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 260718A (trigger 806066200/260718470),
which was also detected by SVOM/ECLAIRs (S. Antier et al. 2026, GCN 45177).
The Fermi GBM on-ground location is consistent with the SVOM/ECLAIRs position.

The angle from the Fermi LAT boresight is 31 degrees.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 19 s (50-300 keV). The time-averaged spectrum
from T0-3.8 to T0+16.3 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.29 +/- 0.05 and the cutoff energy,
parameterized as Epeak, is 68 +/- 3 keV.

The event fluence (10-1000 keV) in this time interval is
(6.8 +/- 0.6)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-2.4 s in the 10-1000 keV band is 2.1 +/- 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/"