Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 30763

GRB 210904A: Fermi GBM Final Real-time Localization
2021-09-04T20:58:06Z (3 years ago)
Fermi GBM Team at MSFC/Fermi-GBM <>
The Fermi GBM team reports the detection of a likely SHORT GRB

At 20:47:39 UT on 4 Sep 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210904A (trigger 652481264.630844 / 210904866).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 121.1, Dec = -44.0 (J2000 degrees, equivalent to J2000 08h 04m, -44d 00'), with a statistical uncertainty of 9.2 degrees.

The angle from the Fermi LAT boresight is 104.0 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:
Looking for U.S. government information and services? Visit