{
  "circularId": 43835,
  "body": "P. Veres (UAH) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 04:11:09.81 UT on 23 February 2026, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 260223A (trigger 793512674/260223174),\nwhich was also detected by \nDDOTI (Becerra et al. 2026, GCN 43811),\nCOLIBRI (de Ugarte Postigo  et al. 2026, GCNs 43812, 43814 & 43820),\nSVOM/GRM  (Wang et al. 2026, GCN 43815),\nSVOM/VT  (Li et al. 2026, GCN 43816) and\nGlowbug  (Woolf et al. 2026, GCN 43824).\n\nThe Fermi GBM on-ground location (GCN 43808) is consistent with the DDOTI position.\n\nThe angle from the Fermi LAT boresight is 33 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 39 s (50-300 keV). The time-averaged spectrum\nfrom T0-9.2 to T0+51.2 s is best fit by\na Band function with Epeak = 70 +/- 6 keV,\nalpha = -0.76 +/- 0.09, and beta = -1.91 +/- 0.02.\n\nThe event fluence (10-1000 keV) in this time interval is\n(2.16 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+18 s in the 10-1000 keV band is 10.4 +/- 0.3 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/\"",
  "subject": "GRB 260223A: Fermi GBM Observation",
  "submittedHow": "web",
  "submitter": "Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>",
  "eventId": "GRB 260223A",
  "bibcode": "2026GCN.43835....1V",
  "format": "text/plain",
  "createdOn": 1772039817723
}