GCN Circular 42215
Subject
GRB 251013B: Fermi GBM Final Real-time Localization
Event
Date
2025-10-13T08:33:39Z (a day ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 08:24:27 UT on 13 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251013B (trigger 782036672.403254 / 251013350).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 356.5, Dec = 7.5 (J2000 degrees, equivalent to J2000 23h 45m, 7d 30'), with a statistical uncertainty of 5.7 degrees.
The angle from the Fermi LAT boresight is 87.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251013350/quicklook/glg_skymap_all_bn251013350.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251013350/quicklook/glg_healpix_all_bn251013350.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251013350/quicklook/glg_lc_medres34_bn251013350.gif