TITLE:   GCN CIRCULAR
NUMBER:  41895
SUBJECT: GRB 250920A: Fermi GBM Final Localization
DATE:    25/09/20 05:05:52 GMT
FROM:    Jacob Smith at Fermi-GBM Team <jrs0118@uah.edu>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 02:54:06.82 UT on 20 September 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250920 (trigger 780029651/250920121).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 175.27, Dec = 48.96 (J2000 degrees, equivalent to J2000 11h 41m, +48d 57'),
with a statistical uncertainty of 1.00 degrees.

The angle from the Fermi LAT boresight is 88 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250920121/quicklook/glg_skymap_all_bn250920121.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250920121/quicklook/glg_healpix_all_bn250920121.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250920121/quicklook/glg_lc_medres34_bn250920121.gif"