{
  "bibcode": "2025GCN.40114....1M",
  "eventId": "GRB 250407A",
  "subject": "GRB 250407A: Fermi GBM Detection",
  "submitter": "oindabimukherjee@gmail.com",
  "submittedHow": "web",
  "createdOn": 1744075696967,
  "circularId": 40114,
  "format": "text/plain",
  "body": "O. Mukherjee (USRA) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 15:48:21.07 UT on 07 April 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 250407A (trigger 765733706/250407659). \nThe afterglow was detected by ART-XC (Molkov et al. 2025, GCN 40110) \nand Swift-XRT (Dichiara et al. 2025, GCN 40113).\n\nThe Fermi GBM Final Localization (GCN 40104) is consistent with the ART-XC\nand Swift-XRT positions.\n\nThe angle from the Fermi LAT boresight is 116 degrees.\n\nThe GBM light curve consists of a single-peak emission episode with a duration (T90)\nof about 6.3 s (50-300 keV). The time-averaged spectrum\nfrom T0+0.6 to T0+5.1 s is best fit by\na Band function with Epeak = 470 +/- 20 keV,\nalpha = -0.18 +/- 0.03, and beta = -2.08 +/- 0.03.\n\nThe event fluence (10-1000 keV) in this time interval is\n(2.65 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+0.77 s in the 10-1000 keV band is 62.4 +/- 0.7 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/\""
}