TITLE:   GCN CIRCULAR
NUMBER:  40887
SUBJECT: GRB 250702A: Fermi GBM Detection
DATE:    25/07/02 15:35:45 GMT
FROM:    Christian Malacaria at INAF-OAR <cmalacaria.astro@gmail.com>

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

"At 09:54:07.56 UT on 02 July 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250702A (trigger 773142852/250702413).
The Fermi-GBM position was reported in GCN 40883 (Fermi GBM Team 2025).

The angle from the Fermi LAT boresight is 56 degrees.

The GBM light curve consists of a single bright emission episode with a duration (T90)
of about 52.7 s (50-300 keV). The time-averaged spectrum
from T0 to T0+69 s is best fit by a Band function 
with Epeak= 242 +/- 9 keV, alpha =-0.57 +/- 0.03 and beta =-2.6 +/- 0.2.

A power law function with an exponential high-energy cutoff
fits the spectrum equally well with a power law index of -0.61 +/- 0.02 
and a cutoff energy, parameterized as Epeak, of 262 +/- 7 keV.

The event fluence (10-1000 keV) in this time interval is
(3.84 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.9 s in the 10-1000 keV band is 12.8 +/- 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/"