TITLE: GCN CIRCULAR NUMBER: 41896 SUBJECT: GRB 250920A: BALROG localization (Fermi Trigger 780029651 / GRB 250920121) DATE: 25/09/20 05:33:44 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 780029651 at 02:54:06 on 20 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) = 174.6 deg Decl.(2000.0) = 52.8 deg The 1 sigma statistical error radius is 1.9 deg. We estimate an additional systematic error of 2 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB250920121/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB250920121/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB250920121/json View this GCN Circular online at https://gcn.nasa.gov/circulars/41896. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...