Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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.

Advanced Search Examples (click to copy):

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

19 results found.

  1. Konus-Wind detection of GRB 240204A
  2. Fermi-LAT gamma-ray observations of IceCube-240204A
  3. GRB240204A: Swift/UVOT Upper Limits
  4. GRB 240204A: AstroSat CZTI detection
  5. GRB 240204A: Mondy optical afterglow observations
  6. GRB 240204A : OHP/T193/T120 optical afterglow fading detection
  7. GRB 240204A: Swift-BAT refined analysis
  8. GRB 240204A: Fermi GBM Observation
  9. GRB 240204a: Liverpool Telescope optical afterglow detection
  10. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  11. IceCube-240204A: Upper limits from a search for additional neutrino events in IceCube
  12. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  13. GRB 240204A: Montarrenti Observatory optical observations
  14. GRB 240204A: Enhanced Swift-XRT position
  15. GRB 240204A: Mondy optical afterglow candidate
  16. Fermi GRB 240204A: Global MASTER-Net observations report
  17. GRB 240204A: Swift detection of a burst
  18. IceCube-240204A - IceCube observation of a high-energy neutrino candidate track-like event
  19. GRB 240204A: Fermi GBM Final Real-time Localization

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov