Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 33035

GRB 221209B: Fermi GBM Final Real-time Localization
2022-12-09T21:13:45Z (a year ago)
Fermi GBM Team at MSFC/Fermi-GBM <>
The Fermi GBM team reports the detection of a likely LONG GRB

At 21:03:27 UT on 9 Dec 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221209B (trigger 692312612.788022 / 221209877).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 142.1, Dec = -5.2 (J2000 degrees, equivalent to J2000 09h 28m, -5d 12'), with a statistical uncertainty of 10.6 degrees.

The angle from the Fermi LAT boresight is 92.0 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