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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"

111 results found.

  1. report on BSAX observations of GRB980425
  2. GRB980329 IPN annulus
  3. GRB980329 near-IR observations
  4. GRB980329 near-IR observations
  5. GRB980329 near IR observations
  6. GRB980329 optical observations
  7. Optical Observations for GRB 971227
  8. GRB 971227: Optical observations
  9. GRB971214: Optical Observations and Calibrations
  10. Optical Observations of GRB 971214 at Keck
  11. GRB 971214: USNOFS Observations Summary

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Download all Circulars as a .tar.gz archive:
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