TITLE: GCN CIRCULAR NUMBER: 43088 SUBJECT: GRB 251214B: Fermi GBM Final Real-time Localization DATE: 25/12/14 09:13:00 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 09:02:18 UT on 14 Dec 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251214B (trigger 787395743.028482 / 251214377).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 329.6, Dec = -18.5 (J2000 degrees, equivalent to J2000 21h 58m, -18d 30'), with a statistical uncertainty of 9.3 degrees.

The angle from the Fermi LAT boresight is 91.0 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251214377/q...

The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251214377/q...

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251214377/q...

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