TITLE: GCN CIRCULAR NUMBER: 42830 SUBJECT: GRB 251125A: Fermi GBM Final Real-time Localization DATE: 25/11/25 01:09:58 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 00:59:38 UT on 25 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251125A (trigger 785725183.783164 / 251125041).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 161.9, Dec = -7.6 (J2000 degrees, equivalent to J2000 10h 47m, -7d 35'), with a statistical uncertainty of 7.6 degrees.

The angle from the Fermi LAT boresight is 37.0 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251125041/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/bn251125041/q...

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251125041/q...

View this GCN Circular online at https://gcn.nasa.gov/circulars/42830. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...