Location of GRB250309318

GRB Properties

Parameters calculated by MPE

Property	Value	Error (1 σ statistical)
Trigger Number
Trigger Time	March 09, 2025, 07:38:30
Data Timestamp	March 09, 2025, 09:42:36
Localization Timestamp	March 09, 2025, 13:45:49
Balrog Ra [deg]	210.2	0.5
Balrog Dec [deg]	-7.9	0.6
Error radius 1 σ [deg]	1.1
Error radius 2 σ [deg]	2.0
Estimated systematic error [deg]	1
Fitted Model	cutoff_powerlaw
Spectral Parameter K [photons/cm^2/keV*s]	33	4.4
Spectral Parameter Index	-1.6	0.04
Spectral Parameter XC [keV]	3e+02	6e+01
Satellite Phi [deg]	-150.26
Satellite Theta [deg]	15.26

Parameters from external Source

Property	Value
Swift Ra [deg]
Swift Dec [deg]
Most likely	None None%
Second most likely	None None%

Download healpix file Download healpix file (with sys error)

GRB Location Alert

To circulars@gcn.nasa.gov

GRB 250309B: BALROG localization (Fermi Trigger 763198715 / GRB 250309318)

T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
763198715 at 07:38:30 on 09 March 2025 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 is:
RA(2000.0) = 210.5 deg
Decl.(2000.0) = -7.6 deg
The 1 sigma statistical error radius is 1.3 deg.
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB250309318/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB250309318/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB250309318/json