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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"

23 results found.

  1. IPN triangulation of GRB 231129C
  2. GRB 231129C: ASIM MXGS observation and localization
  3. Konus-Wind detection of GRB 231129C
  4. GRB 231129C: Swift-XRT afterglow detection
  5. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  6. GRB 231129C: AGILE detection
  7. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  8. GRB 231129C: MASTER OT detection
  9. GRB 231129C: Fermi-LAT detection
  10. GRB 231129C: GRBAlpha detection
  11. GRB 231129C: Glowbug gamma-ray detection
  12. GRB 231129C: Swift-XRT observations
  13. GRB 231129C: GECAM-B detection of a bright burst
  14. GRB 231129C: AstroSat CZTI detection
  15. GRB 231129C: iTelescope OT retraction
  16. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  17. GRB 231129C: Fermi GBM Observation of a very bright GRB
  18. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  19. GRB 231129C: Tiled Swift observations
  20. GRB 231129C: MAXI/GSC detection
  21. GRB 231129C: BALROG localization (Fermi Trigger / GRB 231129799)
  22. GRB 231129C: Fermi GBM detection of a very bright burst
  23. GRB 231129C: Fermi GBM Final Real-time Localization

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