GCN Circular 44698
Subject
GRB 260523A: Fermi GBM Final Real-time Localization
Event
Date
2026-05-23T16:16:46Z (6 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 16:06:10 UT on 23 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260523A (trigger 801245175.681708 / 260523671).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 315.6, Dec = -6.8 (J2000 degrees, equivalent to J2000 21h 02m, -6d 47'), with a statistical uncertainty of 5.5 degrees.
The angle from the Fermi LAT boresight is 51.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260523671/quicklook/glg_skymap_all_bn260523671.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/bn260523671/quicklook/glg_healpix_all_bn260523671.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260523671/quicklook/glg_lc_medres34_bn260523671.gif