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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

4 results found.

  1. LIGO/Virgo/KAGRA S240910ci: NED Galaxies in the Localization Volume
  2. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  3. LIGO/Virgo/KAGRA S240910ci: Updated Sky localization and EM Bright Classification
  4. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate

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