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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"

10 results found.

  1. LIGO/Virgo/KAGRA S250830bp: SOAR spectroscopy of two DESGW candidates
  2. LIGO/Virgo/KAGRA S250830bp: DECam/SOAR GW-MMADS updates
  3. LIGO/Virgo/KAGRA S250830bp: DECam DESGW Epoch 2 Candidates
  4. LIGO/Virgo/KAGRA S250830bp: DECam GW-MMADS candidates
  5. LIGO/Virgo/KAGRA S250830bp: DECam DESGW Epoch 1 Candidates
  6. LIGO/Virgo/KAGRA S250830bp: Coverage and upper limits from MAXI/GSC observations
  7. LIGO/Virgo/KAGRA S250830bp GLADEnet Completeness: Potential Host Galaxies in the 90% Credible Volume
  8. LIGO/Virgo/KAGRA S250830bp: NED Galaxies in the 4-Update Localization Volume
  9. LIGO/Virgo/KAGRA S250830bp: Updated Sky localization, EM Bright Classification, and Source Classification
  10. LIGO/Virgo/KAGRA S250830bp: Identification of a GW compact binary merger candidate

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Download all Circulars as a .tar.gz archive:
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