TITLE:   GCN CIRCULAR
NUMBER:  43995
SUBJECT: GRB 260313A: A Correction to the Fermi GBM Final Localization
DATE:    26/03/13 18:31:37 GMT
FROM:    oliver.roberts@universityofgalway.ie

O.J. Roberts (Uni. of Galway, Ireland) reports on behalf of the Fermi
Gamma-ray Burst Monitor Team.

"At 12:00:28.58 UT on 13 March 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 260313A (trigger 795096033/260312500). An on-ground
calculated location, using the Fermi GBM trigger data, was initially reported
in GCN 43987 by the GBM Team.

Further analysis found the location of the short GRB to be inaccurate. We 
report the updated/refined location to be RA = 241.16, Dec = 5.80 (J2000 degrees, 
equivalent to J2000 16h 05m, 05d 48'), with a statistical uncertainty of 5.8 degrees.

The angle from the Fermi LAT boresight with this new position is 15 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260312500/quicklook/glg_skymap_all_bn260312500.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/bn260312500/quicklook/glg_healpix_all_bn260312500.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260312500quicklook/glg_lc_medres34_bn260312500.gif"