{
  "eventId": "GRB 250721A",
  "submittedHow": "web",
  "format": "text/plain",
  "createdOn": 1753281817374,
  "body": "A. Holzmann Airasca (UniTrento and INFN Bari) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 09:37:46.53 UT on 21 July 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 250721A (trigger 774783471/250721401).\nwhich was also detected by MAXI (M. Nakajima et al. 2025, GCN 41129).\nThe Fermi GBM on-ground location is consistent with the MAXI position.\n\nThe angle from the Fermi LAT boresight is 70 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 54 s (50-300 keV). The time-averaged spectrum\nfrom T0-3.1 to T0+1.5 s is best fit by\na simple power law function with index -1.46 +/- 0.07.\n\nThe event fluence (10-1000 keV) in this time interval is\n(9.8 +/- 1.6)E-07 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0-2.5 s in the 10-1000 keV band is 1.7 +/- 0.2 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog:\nhttps://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n\nFor Fermi GBM data and info, please visit the official Fermi GBM Support Page:\nhttps://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "circularId": 41141,
  "submitter": "A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>",
  "subject": "GRB 250721A: Fermi GBM Observation",
  "bibcode": "2025GCN.41141....1H"
}