{
  "submitter": "oliver.roberts@universityofgalway.ie",
  "createdOn": 1769901176781,
  "format": "text/plain",
  "body": "O.J. Roberts (Uni. of Galway, Ireland) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:\n\n\"At 06:39:30.44 UT on 31 January 2026, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 260131A/B (trigger 791534375/260131277).\nwhich was also detected by MAXI (H. Sugai et al. 2026, GCN 43580).\nThe Fermi GBM final real-time Localization (GCN 43579) is consistent with the MAXI position.\nThe MAXI burst triggered on the second pulse of 260131A.\nWe note both bursts have similar locations and are likely the same event. \n\nThe angle from the Fermi LAT boresight using the MAXI location is 112 degrees.\n\nThe GBM light curve consists of two separated FRED emission episodes \nwith a duration (T90) of about 257 s (50-300 keV). The time-averaged spectrum\nfrom T0-2.0 to T0+280.0 s is best fit by a Band function with an \nEpeak of 148 +/- 39 keV, alpha is -0.90 +/- 0.16 and\nbeta is -1.76 +/- 0.06.\n\nThe event fluence (10-1000 keV) in this time interval is\n(2.82 +/- 0.09)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+2.6 s in the 10-1000 keV band is 8.3 +/- 0.4 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/\"",
  "eventId": "GRB 260131A",
  "submittedHow": "web",
  "subject": "GRB 260131A/B: Fermi GBM Observation",
  "bibcode": "2026GCN.43585....1R",
  "circularId": 43585
}