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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.

Lucene Examples (click to copy):

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

37 results found.

  1. GRB 140623A: Swift-XRT and UVOT observations
  2. GRB 140423A: TShAO optical observations
  3. GRB 140423A: HCT optical observations
  4. GRB 140423A: AAO optical upper limits
  5. GRB 140423A: Mondy optical observations
  6. Konus-Wind observation of GRB 140423A
  7. GRB 140423A: RTT150 optical observations
  8. GRB 140423A: MITSuME Akeno upper limits
  9. GRB 140423A Third epoch pODI photometry
  10. GRB 140423A: Continued RATIR Optical and NIR Observations
  11. GRB 140423A: MITSuME Akeno Optical observation
  12. DG CVn: optical observations
  13. GRB 140423A: RATIR Optical and NIR Observations
  14. GRB 140423A: NOT Afterglow Observations
  15. GRB 140423A: Nishi-Harima NIR Observations
  16. GRB 140423A: TNG NIR observations
  17. GRB 140423A pODI/WIYN afterglow photometry
  18. GRB 140423A, Optical Observations
  19. GRB 140423A: Kanata/HONIR Optical and NIR Observations
  20. GRB 140423A: Swift-XRT refined Analysis
  21. GRB 140423A: Swift-BAT refined analysis
  22. GRB 140423A: MITSuME Okayama Optical Observation
  23. GRB 140423A: Further Observations with Swift/UVOT
  24. GRB 140423A: KAIT Optical Detection
  25. GRB 140423A: Enhanced Swift-XRT position
  26. GRB 140423A: Nanshan optical upper limit
  27. GRB 140423A: P60 Observations
  28. GRB 140423A: Fermi GBM observation
  29. GRB 140423A: KWFC z-band photometry
  30. GRB 140423A: Gemini-N redshift
  31. GRB 140423A: ISON-MN early photometry and correction to the GCN circ. 16143
  32. GRB 140423A: Swift/UVOT detection of a possible counterpart
  33. GRB 140423A: Swift-XRT observations
  34. GRB 140423A: ROTSE-III Detection of Optical Counterpart
  35. GRB 140423A optical observations with pODI/WIYN at KPNO
  36. GRB 140423A: optical afterglow candidate
  37. GRB 140423A: Swift detection of a burst

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