{
  "bibcode": "2025GCN.39291....1M",
  "circularId": 39291,
  "body": "O. Mukherjee (USRA), R. Hamburg (USRA) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 01:16:03.15 UT on 07 February 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 250207A (trigger 760583768/250207053).\nwhich was also detected by Swift BAT (Ferro et al. 2025, GCN 39182), COLIBRÍ/DDRAGO (Angulo et al. 2025, GCN 39186), \nSwift/UVOT (Kuin et al. 2025, GCN 39199), and Konus-Wind (Ridnaia. et al. 2025, GCN 39284) \nThe Fermi GBM Final Real-time Localization (GCN 39181)  is consistent with the Swift BAT position.\n\nThe angle from the Fermi LAT boresight is 46 degrees.\n\nThe GBM light curve consistes of a single emission episode with multiple peaks with a duration (T90)\nof about 20 s (50-300 keV). The time-averaged spectrum\nfrom T0-3.1 to T0+25.6 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -1.10 +/- 0.06 and the cutoff energy,\nparameterized as Epeak, is 290 +/- 30 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.04 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+12 s in the 10-1000 keV band is 4.7 +/- 0.3 ph/s/cm^2.\n\nA Band function fits the spectrum equally well\nwith Epeak= 240 +/- 30 keV, alpha = -1.03 +/- 0.08 and beta = -2.3 +/- 0.3.\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/\"",
  "subject": "GRB 250207A: Fermi GBM Observation",
  "createdOn": 1739309506065,
  "submitter": "oindabimukherjee@gmail.com",
  "eventId": "GRB 250207A",
  "submittedHow": "web",
  "format": "text/plain"
}