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GCN Circular 33668

GRB 230421A: Fermi GBM Final Real-time Localization
2023-04-21T13:54:39Z (a year ago)
William Cleveland at NASA-MSFC <>
The Fermi GBM team reports the detection of a likely LONG GRB

At 09:42:46 UT on 21 Apr 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230421A (trigger 703762971.373066 / 230421405).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 44.5, Dec = 6.0 (J2000 degrees, equivalent to J2000 02h 58m, 6d 00'), with a statistical uncertainty of 5.5 degrees.

The angle from the Fermi LAT boresight is 99.0 degrees.

The skymap can be found here:

The HEALPix FITS file, including the estimated localization systematic, can be found here:

The GBM light curve can be found here:

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