Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 29659

GRB 210317A: Fermi GBM Final Real-time Localization
2021-03-17T09:18:31Z (3 years ago)
Fermi GBM Team at MSFC/Fermi-GBM <>
The Fermi GBM team reports the detection of a likely LONG GRB

At 09:08:29 UT on 17 Mar 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210317A (trigger 637664914.045098 / 210317381).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 154.2, Dec = -64.9 (J2000 degrees, equivalent to J2000 10h 16m, -64d 54'), with a statistical uncertainty of 1.5 degrees.

The angle from the Fermi LAT boresight is 159.0 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