TITLE:   GCN CIRCULAR
NUMBER:  42293
SUBJECT: GRB 251015A: Fermi GBM Final Real-time Localization
DATE:    25/10/15 16:19:34 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 16:08:49 UT on 15 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251015A (trigger 782237334.425736 / 251015673).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 355.1, Dec = -56.1 (J2000 degrees, equivalent to J2000 23h 40m, -56d 06'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 167.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251015673/quicklook/glg_skymap_all_bn251015673.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/bn251015673/quicklook/glg_healpix_all_bn251015673.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251015673/quicklook/glg_lc_medres34_bn251015673.gif