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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"

25025 results found.

  1. GRB980329 sub-millimeter observations
  2. GRB980329 optical observations
  3. GRB980329 near-IR observations
  4. GRB980329 near-IR observations
  5. GRB980326 optical observations
  6. GRB980329 optical observations
  7. GRB980329 VLA observations
  8. GRB980329 optical observations
  9. GRB980329 optical observations
  10. GRB980326 optical observations
  11. GRB980326 optical observations
  12. Optical Observations of GRB 970508
  13. Near-IR follow-up on GRB 971227
  14. Optical Observations of the GRB 971227 field
  15. Optical Observations on GRB 971227
  16. GRB971227: Plaskett R-band observations
  17. GRB 971227: Optical clarifications
  18. GRB971227: Further CAHA R-band images
  19. GRB971227: LOTIS observations
  20. GRB971214: Optical Observations and Calibrations
  21. GRB 971214: Optical Observations
  22. Radio Observations of GRB 971214 at the VLA
  23. GRB 971024: Refined analysis by USNOFS Observations
  24. GRB 971024: KPNO Optical Observations
  25. GRB 970828: Palomar Observations

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