TITLE:   GCN CIRCULAR
NUMBER:  46123
SUBJECT: GRB 261101A: Fermi GBM Final Real-time Localization
DATE:    26/11/01 05:27:36 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 SHORT GRB

At 05:17:13 UT on 1 Nov 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 261101A (trigger 815203038.574874 / 261101220).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 177.9, Dec = -17.2 (J2000 degrees, equivalent to J2000 11h 51m, -17d 11'), with a statistical uncertainty of 11.2 degrees.

The angle from the Fermi LAT boresight is 45.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261101220/quicklook/glg_skymap_all_bn261101220.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/bn261101220/quicklook/glg_healpix_all_bn261101220.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261101220/quicklook/glg_lc_medres34_bn261101220.gif