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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. Konus-Wind detection of GRB 250702F
  2. GRB 250702F: GROWTH-India Telescope optical observations
  3. GRB 250702F: optical photometry from Konkoly
  4. GRB 250702F: SVOM/VT optical observation
  5. GRB 250702F: Swift/UVOT Detection
  6. GRB 250702F: Swift-XRT refined Analysis
  7. GRB 250702F: Fermi GBM Observation
  8. GRB 250702F: Leavitt Observatory optical observations
  9. GRB 250702F: AKO Optical Afterglow Detection
  10. GRB 250702F: Skynet Optical Observations
  11. GRB 250702F: TRT Optical Observation
  12. GRB 250702F: REM optical afterglow detection
  13. GRB 250702F: DDOTI Optical Observation
  14. GRB 250702F: COLIBRÍ Observations of the Afterglow
  15. GRB 250702F: Enhanced Swift-XRT position
  16. GRB 250702F: GTC/OSIRIS+ spectroscopic redshift z = 1.520
  17. GRB 250702F: NOT observations of the optical afterglow
  18. GRB 250702F: MASTER optical afterglow observation
  19. Fermi GRB 250702F: Global MASTER-Net observations report
  20. GRB 250702F: GOTO optical counterpart detection
  21. GRB 250702F: Ondrejov D50 optical afterglow detection
  22. GRB 250702F: Swift detection of a burst with an optical counterpart
  23. GRB 250702F: Fermi GBM Final Real-time Localization

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