TITLE: GCN CIRCULAR NUMBER: 36910 SUBJECT: GRB 240720A: Fermi GBM observation DATE: 24/07/20 16:27:50 GMT FROM: Cori Fletcher at USRA <cfletcher@usra.edu> C. Fletcher (USRA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 00:24:51.22 UT on 20 July 2024, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 240720A (trigger 743127896 / 240720017), which was also detected by the Swift/BAT (Gupta et al. 2024, GCN 36909) and INTEGRAL SPI/ACS (trigger 10797). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 47 degrees. The GBM light curve consists of multiple peaks with a duration (T90) of about 1.8 s (50-300 keV). The time-averaged spectrum from T0+0.002 s to T0+2.176 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.66 +/- 0.07 and the cutoff energy, parameterized as Epeak, is 1069 +/- 172 keV. The event fluence (10-1000 keV) in this time interval is (3.9 +/- 0.1)E-06 erg/cm^2. The 64-ms peak photon flux measured starting from T0+0.896 s in the 10-1000 keV band is 9.1 +/- 1.0 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/36910. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...