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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"

28 results found.

  1. GRB 250419A: Mondy Optical Observations
  2. GRB 250419a: Continued Liverpool Telescope observations
  3. GRB 250419A: Liverpool Telescope optical upper limit
  4. GRB 250419A: SVOM/ECLAIRs refined analysis
  5. GRB250419A: VLA radio detection
  6. GRB 250419A: Mephisto Multi-band Optical Detection
  7. GRB 250419A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
  8. GRB 250419A: Optical Observations via Virtual Telescope Project
  9. GRB 250419A: Mondy Continued Optical Observations
  10. GRB 250419A: Liverpool Telescope observations
  11. GRB 250419A: LCO optical observation
  12. GRB 250419A: JinShan optical observations
  13. GRB 250419A: SVOM/VT optical continuous observations
  14. GRB 250419A: SVOM/C-GFT optical observations
  15. GRB 250419A: Swift/UVOT Follow up
  16. GRB 250419A: LCO optical afterglow multi-band observations
  17. GRB 250419A: Mondy and AbAO Optical Observations
  18. GRB 250419A: Liverpool Telescope observations
  19. GRB 250419A: AKO Optical Afterglow Detection
  20. GRB 250419A: MASTER optical afterglow observation
  21. GRB 250419A: Swift-XRT localisation
  22. GRB 250419A: VLT/X-shooter spectroscopic redshift z = 0.845
  23. GRB 250419A: Swift-XRT refined Analysis
  24. GRB 250419A: GOTO optical counterpart detection
  25. GRB 250419A: KAIT optical afterglow observations
  26. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  27. GRB 250419A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
  28. GRB 250419A: SVOM detection of a soft burst

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