TITLE:   GCN CIRCULAR
NUMBER:  30105
SUBJECT: GRB 210531A: BALROG localization (Fermi Trigger 644155206 / GRB 210531500)
DATE:    21/05/31 12:24:39 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
644155206 at 12:00:01 on 31 May 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) = 140.9+/-0.5 deg
Decl.(2000.0) = 6.1+/-0.7 deg
We estimate an additional systematic error of 2 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB210531500/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB210531500/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB210531500/json