TITLE: GCN CIRCULAR NUMBER: 31030 SUBJECT: GRB 211102A: BALROG localization (Fermi Trigger 657533168 / GRB 211102338) DATE: 21/11/02 08:25:00 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 657533168 at 08:06:03 on 02 Nov. 2021 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) = 37.1+/-3.1 deg Decl.(2000.0) = 52.5+/-2.3 deg We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB211102338/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB211102338/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB211102338/json