GCN Circular 45028
Subject
GRB 260623A: Fermi GBM Final Real-time Localization
Event
Date
2026-06-23T13:09:24Z (16 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 12:56:49 UT on 23 Jun 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260623A (trigger 803912214.021094 / 260623539).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 39.3, Dec = -10.4 (J2000 degrees, equivalent to J2000 02h 37m, -10d 24'), with a statistical uncertainty of 11.8 degrees.
The angle from the Fermi LAT boresight is 88.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260623539/quicklook/glg_skymap_all_bn260623539.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/bn260623539/quicklook/glg_healpix_all_bn260623539.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260623539/quicklook/glg_lc_medres34_bn260623539.gif