TITLE: GCN CIRCULAR NUMBER: 31033 SUBJECT: GRB 211102B: BALROG localization (Fermi Trigger 657554740 / GRB 211102587) DATE: 21/11/02 14:24:49 GMT FROM: Jochen Greiner at MPE,Garching jcg@mpe.mpg.de

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 657554740 at 14:05:35 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) = 315.4+/-3.0 deg Decl.(2000.0) = 1.5+/-1.5 deg We estimate an additional systematic error of 2 deg.

Further details are available at: https://grb.mpe.mpg.de/grb/GRB211102587/

The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB211102587/healpix

The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB211102587/json