This is the Analysis page for GRB201218177: GRB201218177

Version History of Data Files: v01 v00

GRB Properties

Parameters calculated by MPE

Property Value Error (1 σ statistical)
Trigger Number 629957660
Trigger Time Dec. 18, 2020, 04:14:15
Data Timestamp Dec. 18, 2020, 05:17:04
Localization Timestamp Dec. 18, 2020, 06:53:07
Balrog Ra [deg] 287.3 0.2
Balrog Dec [deg] 26.9 0.3
Error radius 1 σ [deg] 0.3
Error radius 2 σ [deg] 0.7
Estimated systematic error [deg] 1
Fitted Model cutoff_powerlaw
Spectral Parameter K [photons/cm^2/keV*s] 6.9 0.23
Spectral Parameter Index -0.89 0.0083
Spectral Parameter XC [keV] 5e+02 1e+01
Satellite Phi [deg] -15.72
Satellite Theta [deg] -7.97

Parameters from external Source

Property Value
Swift Ra [deg]
Swift Dec [deg]
Most likely GRB 80.0%
Second most likely CYG_X1 15.0%

GRB Location Alert

GRB 201218A: BALROG localization (Fermi Trigger 629957660 / GRB 201218177)

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
629957660 at 04:14:15 on 18 Dec. 2020 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) = 287.38+/-0.29 deg
Decl.(2000.0) = 26.80+/-0.30 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:

The Healpix map can be downloaded from:

The location parameters are available as JSON at:

GRB Location

J2000 Coordinate Frame

All Corner Plot

J2000 Coordinate Frame

Moll Location Plot

J2000 Coordinate Frame


Spectrum Residuals Plot

3D - GRB Location Plot

Satellite Coordiante Frame

Light Curves

Lightcurve detector b0
Lightcurve detector b1
Lightcurve detector n0
Lightcurve detector n1
Lightcurve detector n2
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Lightcurve detector n4
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Lightcurve detector n9
Lightcurve detector na
Lightcurve detector nb