TITLE:   GCN CIRCULAR
NUMBER:  44599
SUBJECT: GRB 260513A: Fermi GBM Final Real-time Localization
DATE:    26/05/13 21:34:57 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 21:24:18 UT on 13 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260513A (trigger 800400263.713514 / 260513892).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 320.8, Dec = -36.4 (J2000 degrees, equivalent to J2000 21h 23m, -36d 23'), with a statistical uncertainty of 2.3 degrees.

The angle from the Fermi LAT boresight is 65.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260513892/quicklook/glg_skymap_all_bn260513892.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/bn260513892/quicklook/glg_healpix_all_bn260513892.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260513892/quicklook/glg_lc_medres34_bn260513892.gif