TITLE:   GCN CIRCULAR
NUMBER:  43804
SUBJECT: GRB 260222A: Fermi GBM Final Real-time Localization
DATE:    26/02/22 10:20:22 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 10:09:38 UT on 22 Feb 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260222A (trigger 793447783.750804 / 260222423).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 336.2, Dec = 61.7 (J2000 degrees, equivalent to J2000 22h 24m, 61d 42'), with a statistical uncertainty of 4.4 degrees.

The angle from the Fermi LAT boresight is 36.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260222423/quicklook/glg_skymap_all_bn260222423.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/bn260222423/quicklook/glg_healpix_all_bn260222423.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260222423/quicklook/glg_lc_medres34_bn260222423.gif