GCN Circular 46019
Subject
GRB 261024A: Fermi GBM Final Real-time Localization
Event
Date
2026-10-24T16:33:31Z (4 days 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 16:23:00 UT on 24 Oct 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 261024A (trigger 814551785.78892 / 261024683).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 317.0, Dec = 63.1 (J2000 degrees, equivalent to J2000 21h 07m, 63d 06'), with a statistical uncertainty of 1.6 degrees.
The angle from the Fermi LAT boresight is 49.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261024683/quicklook/glg_skymap_all_bn261024683.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261024683/quicklook/glg_healpix_all_bn261024683.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261024683/quicklook/glg_lc_medres34_bn261024683.gif