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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.

Lucene Examples (click to copy):

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

3 results found.

  1. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  2. LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
  3. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate

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Download all Circulars as a .tar.gz archive:
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