TITLE: GCN CIRCULAR NUMBER: 41779 SUBJECT: GRB 250910B: BALROG localization (Fermi Trigger 779223130 / GRB 250910786) DATE: 25/09/10 19:25:58 GMT FROM: Jochen Greiner at MPE T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 779223130 at 18:52:05 on 10 Sept. 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) = 74.2 deg Decl.(2000.0) = -47.5 deg The 1 sigma statistical error radius is 3.6 deg. We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB250910786/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB250910786/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB250910786/json