GCN 43104: GRB 251215A: Fermi GBM Final Real-time Localization

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

At 04:21:21 UT on 15 Dec 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251215A (trigger 787465286.567966 / 251215181).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 112.8, Dec = -43.7 (J2000 degrees, equivalent to J2000 07h 31m, -43d 42'), with a statistical uncertainty of 7.6 degrees.

The angle from the Fermi LAT boresight is 31.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251215181/quicklook/glg_skymap_all_bn251215181.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/bn251215181/quicklook/glg_healpix_all_bn251215181.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251215181/quicklook/glg_lc_medres34_bn251215181.gif