TITLE:   GCN CIRCULAR
NUMBER:  38836
SUBJECT: GRB 250107A: Fermi GBM Final Real-time Localization
DATE:    25/01/07 05:12:57 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 05:02:30 UT on 7 Jan 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250107A (trigger 757918955.285842 / 250107210).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 309.4, Dec = 45.3 (J2000 degrees, equivalent to J2000 20h 37m, 45d 17'), with a statistical uncertainty of 3.5 degrees.

The angle from the Fermi LAT boresight is 23.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250107210/quicklook/glg_skymap_all_bn250107210.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/bn250107210/quicklook/glg_healpix_all_bn250107210.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250107210/quicklook/glg_lc_medres34_bn250107210.gif