GCN Circular 36762

C. de Barra (UCD) and C. Meegan (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

At 07:32:40.63 UT on 25 June 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240625A (trigger 740993565/240625314). The Final Real-time Localization was reported previously (Fermi GBM Team 2024, GCN 36758

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 0.15 s (50-300 keV). The time-averaged spectrum from T0+0 to T0+0.192 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.94 +/- 0.08 and the cutoff energy, parameterized as Epeak, is 113 +/- 6 keV.

The spectrum is equally well fit by a Band function with Epeak= 107 +/- 9 keV, alpha = -0.88 +/- 0.10 and beta = -3.00 +/- 0.46.

The event fluence (10-1000 keV) in this time interval is (7.5 +/- 0.3)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0+0.0 s in the 10-1000 keV band is 109 +/- 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/"