Skip to main content
New GCN Circulars features for September 2023! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').

4 results found.

  1. LIGO/Virgo/KAGRA S230520ae: Updated Sky localization
  2. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  3. LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
  4. LIGO/Virgo/KAGRA S230520ae: Upper limits from IceCube neutrino search


Looking for U.S. government information and services? Visit