TITLE: GCN CIRCULAR NUMBER: 36762 SUBJECT: GRB 240625A: Fermi GBM Observation DATE: 24/06/25 18:24:37 GMT FROM: Cuán de Barra at UCD <cuan.debarra@ucdconnect.ie> 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/" View this GCN Circular online at https://gcn.nasa.gov/circulars/36762. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...