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/" View this GCN Circular online at https://gcn.nasa.gov/circulars/40887. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...