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 30754

GRB 210903B: Fermi GBM Final Localization
2021-09-03T16:37:03Z (3 years ago)
Joshua Wood at MSFC/Fermi-GBM <>
The Fermi GBM team reports the detection of a likely SHORT GRB

At 00:30:46.05 UT on 3 Sep 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210903B (trigger 652321851 / 210903021).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 270.9, Dec = +15.6 (J2000 degrees, equivalent to J2000 18h 03m, +15d 36'), with a statistical uncertainty of 26.1 degrees.

The angle from the Fermi LAT boresight is 66.0 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