TITLE:   GCN CIRCULAR
NUMBER:  42526
SUBJECT: GRB 251031A: BALROG localization (Fermi Trigger 783588065 / GRB 251031306)
DATE:    25/10/31 07:43:38 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
783588065 at 07:21:00 on 31 Oct. 2025 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position is:
RA(2000.0) = 188.3 deg
Decl.(2000.0) = -17.9 deg
The 1 sigma statistical error radius is 2.8 deg.
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB251031306/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB251031306/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB251031306/json