GCN Circular 41475
Subject
GRB 250821B: BALROG localization (Fermi Trigger / GRB 250821672)
Event
Date
2025-08-21T19:57:25Z (3 days ago)
From
Jochen Greiner at MPE <jcgrog@mpe.mpg.de>
Via
email
T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
at 16:07:47 on 21 Aug. 2025 were manually 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 is:
RA(2000.0) = 60.0 deg
Decl.(2000.0) = -84.7 deg
The 1 sigma statistical error radius is 2.0 deg.
We estimate an additional systematic error of 2 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB250821672/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB250821672/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB250821672/json