{
  "bibcode": "2025GCN.40060....1V",
  "format": "text/plain",
  "eventId": "GRB 250403A",
  "subject": "GRB 250403A: Fermi GBM observations",
  "createdOn": 1743784310244,
  "circularId": 40060,
  "body": "P. Veres (UAH), M. Godwin (UAH), C. Meegan (UAH) and E. Bissaldi (Politecnico and INFN Bari)\nreport on behalf of the Fermi GBM Team:\n\n\"At 15:15:22.83 UT on 03 April 2025, the Fermi Gamma-Ray Burst Monitor (GBM)\ntriggered and located GRB 250403A (trigger 765386127 / 250403636).\nThis GRB was also detected by the SVOM (Julakanti et al. 2025, GCN 40026).\nThe Fermi GBM Final Real-time Localization (GCN 40025) is consistent with the SVOM position.\n\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 59 degrees.\n\nThe GBM light curve consists of multiple pulses\nwith a duration (T90) of about 16.4 s (50-300 keV).\nThe time-averaged spectrum from T0-4.1 s to T0+14.3 s is\nbest fit by a simple power law function with index -1.65 +/- 0.02.\n\nThe event fluence (10-1000 keV) in this time interval is\n(6.7 +/- 0.2)E-6 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+3.3 s in the 10-1000 keV band\nis 4.2 +/- 0.2 ph/s/cm^2.\n\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/\"",
  "submitter": "Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>",
  "submittedHow": "web"
}