Skip to main content
Circulars over Kafka event name backfill. 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').
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"

9 results found.

  1. GRB 180204A: 15 GHz upper limits from AMI
  2. GRB 180204A: MITSuME Okayama optical upper limits
  3. Konus-Wind observation of GRB 180204A
  4. GRB 180204A: Swift-BAT refined analysis
  5. GRB 180204A: Swift/UVOT Upper Limits
  6. GRB 180204A: Fermi GBM detection
  7. GRB 180204A: Enhanced Swift-XRT position
  8. GRB 180204A: Swift-XRT refined Analysis
  9. GRB 180204A: Swift detection of a short burst

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov