TITLE:   GCN CIRCULAR
NUMBER:  44948
SUBJECT: GRB 260616A: Fermi GBM Final Real-time Localization
DATE:    26/06/16 03:34:02 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 03:21:54 UT on 16 Jun 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260616A (trigger 803272919.330008 / 260616140).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 95.0, Dec = -31.9 (J2000 degrees, equivalent to J2000 06h 19m, -31d 53'), with a statistical uncertainty of 1.4 degrees.

The angle from the Fermi LAT boresight is 111.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260616140/quicklook/glg_skymap_all_bn260616140.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/bn260616140/quicklook/glg_healpix_all_bn260616140.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260616140/quicklook/glg_lc_medres34_bn260616140.gif