TITLE: GCN CIRCULAR NUMBER: 31400 SUBJECT: GRB 220107A: BALROG localization (Fermi Trigger 663259536 / GRB 220107615) DATE: 22/01/07 15:05:36 GMT FROM: Jochen Greiner at MPE,Garching F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 663259536 at 14:45:31 on 07 Jan. 2022 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 (1 sigma statistical errors) is: RA(2000.0) = 168.5+/-1.4 deg Decl.(2000.0) = 34.9+/-1.0 deg We estimate an additional systematic error of 2 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB220107615/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB220107615/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB220107615/json