TITLE:   GCN CIRCULAR
NUMBER:  44774
SUBJECT: GRB 260602A: Fermi GBM Final Real-time Localization
DATE:    26/06/02 18:40:24 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 LONG GRB

At 18:29:53 UT on 2 Jun 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260602A (trigger 802117798.896848 / 260602771).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 26.3, Dec = 48.7 (J2000 degrees, equivalent to J2000 01h 45m, 48d 42'), with a statistical uncertainty of 2.0 degrees.

The angle from the Fermi LAT boresight is 28.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260602771/quicklook/glg_skymap_all_bn260602771.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/bn260602771/quicklook/glg_healpix_all_bn260602771.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260602771/quicklook/glg_lc_medres34_bn260602771.gif