TITLE:   GCN CIRCULAR
NUMBER:  44969
SUBJECT: GRB 260617A: Fermi GBM Final Real-time Localization
DATE:    26/06/17 21:49:10 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 21:36:43 UT on 17 Jun 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260617A (trigger 803425008.678884 / 260617900).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 236.9, Dec = -16.7 (J2000 degrees, equivalent to J2000 15h 47m, -16d 41'), with a statistical uncertainty of 12.7 degrees.

The angle from the Fermi LAT boresight is 100.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260617900/quicklook/glg_skymap_all_bn260617900.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/bn260617900/quicklook/glg_healpix_all_bn260617900.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260617900/quicklook/glg_lc_medres34_bn260617900.gif