TITLE: GCN CIRCULAR NUMBER: 29905 SUBJECT: GRB 210427A: BALROG localization (Fermi Trigger / GRB 210427206) DATE: 21/04/27 07:48:15 GMT FROM: Jochen Greiner at MPE,Garching B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger at 04:57:12 on 27 April 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) = 172.6+/-2.5 deg Decl.(2000.0) = -54.4+/-1.7 deg We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB210427206/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB210427206/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB210427206/json