GCN Circular 44335
Subject
GRB 260418A: Fermi GBM Final Real-time Localization
Event
Date
2026-04-18T05:00:17Z (12 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 SHORT GRB
At 04:49:35 UT on 18 Apr 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260418A (trigger 798180580.203356 / 260418201).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 140.6, Dec = 29.3 (J2000 degrees, equivalent to J2000 09h 22m, 29d 18'), with a statistical uncertainty of 18.1 degrees.
The angle from the Fermi LAT boresight is 60.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260418201/quicklook/glg_skymap_all_bn260418201.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/bn260418201/quicklook/glg_healpix_all_bn260418201.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260418201/quicklook/glg_lc_medres34_bn260418201.gif