TITLE: GCN CIRCULAR NUMBER: 42502 SUBJECT: GRB 251028B: Fermi GBM Final Localization Correction DATE: 25/10/28 10:12:02 GMT FROM: Christian Malacaria at INAF-OAR cmalacaria.astro@gmail.com
The Fermi GBM team reports the detection of a likely LONG GRB
"At 07:48:06.71 UT on 28 October 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251028B (trigger 783330491/251028325). This trigger was initially classified as Distant Particles by the flight software, but is in fact a GRB.
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 337.82, Dec = 45.75 (J2000 degrees, equivalent to J2000 22h 31m, +45d 45'), with a statistical uncertainty of 3.69 degrees.
The angle from the Fermi LAT boresight is 119 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251028325/q...
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251028325/q...
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251028325/q..."
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