TITLE:   GCN CIRCULAR
NUMBER:  45788
SUBJECT: GRB 260930A: Fermi GBM Final Real-time Localization
DATE:    26/09/30 20:09:49 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 19:59:09 UT on 30 Sep 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260930A (trigger 812491154.688938 / 260930833).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 175.2, Dec = -7.3 (J2000 degrees, equivalent to J2000 11h 40m, -7d 17'), with a statistical uncertainty of 8.1 degrees.

The angle from the Fermi LAT boresight is 61.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260930833/quicklook/glg_skymap_all_bn260930833.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/bn260930833/quicklook/glg_healpix_all_bn260930833.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260930833/quicklook/glg_lc_medres34_bn260930833.gif