TITLE:   GCN CIRCULAR
NUMBER:  44115
SUBJECT: GRB 260326A: Fermi GBM Final Real-time Localization
DATE:    26/03/26 01:28:58 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 01:18:28 UT on 26 Mar 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260326A (trigger 796180713.505606 / 260326054).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 97.9, Dec = 25.4 (J2000 degrees, equivalent to J2000 06h 31m, 25d 23'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 76.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260326054/quicklook/glg_skymap_all_bn260326054.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/bn260326054/quicklook/glg_healpix_all_bn260326054.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260326054/quicklook/glg_lc_medres34_bn260326054.gif