TITLE:   GCN CIRCULAR
NUMBER:  39741
SUBJECT: GRB 250316A: Fermi GBM Final Real-time Localization
DATE:    25/03/16 09:10:17 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 08:59:57 UT on 16 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250316A (trigger 763808402.691648 / 250316375).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 208.7, Dec = 24.2 (J2000 degrees, equivalent to J2000 13h 54m, 24d 11'), with a statistical uncertainty of 10.2 degrees.

The angle from the Fermi LAT boresight is 94.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250316375/quicklook/glg_skymap_all_bn250316375.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/bn250316375/quicklook/glg_healpix_all_bn250316375.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250316375/quicklook/glg_lc_medres34_bn250316375.gif