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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"

346 results found.

  1. Optical report on X-ray/GRB transient
  2. BeppoSAX: A new fast X-ray transient
  3. GRB981220 VLBA observations
  4. GRB981220, IPN localization
  5. GRB 981220, radio observations
  6. GRB990123, Probability of gravitational lensing
  7. GRB990123 IPN annulus
  8. GRB990123, refined SAX-WFC position
  9. GRB 990123, Radio observations
  10. Optical Observations of GRB 981220
  11. GRB981220
  12. GRB981220, Optical Observations
  13. GRB 981220 Optical observations
  14. GRB 981226 Optical Observations
  15. GRB981220, sub-millimeter observations
  16. GRB 981220 and GRB 981226, optical observations
  17. GRB981226 BeppoSAX follow up
  18. GRB981220 B, R and I band observations
  19. GRB 981220:Optical Observations
  20. GRB 981220
  21. GRB980425: X-ray revised positions
  22. GRB980519, Optical Observations
  23. GRB980703, Host galaxy multicolor photometry
  24. GRB 980703 (NFI observations)
  25. BeppoSAX NFI observations of GRB 980703
  26. GRB980703
  27. GRB980613, optical observations
  28. GRB 980613 Optical Observations
  29. GRB980613 BeppoSAX-NFI follow up
  30. GRB980613, BeppoSAX WFC positions
  31. GRB980519 IPN POSITION
  32. GRB980515: SAX-WFC updated position
  33. BSAX Observations of GRB980425 field
  34. GRB980425 BATSE observations
  35. SAX J0840.7+2248 Optical Observations
  36. report on BSAX observations of GRB980425
  37. GRB980329 IPN annulus
  38. GRB980329 near-IR observations
  39. GRB980329 near-IR observations
  40. GRB980329 near IR observations
  41. GRB980329 optical observations
  42. Optical Observations for GRB 971227
  43. GRB 971227: Optical observations
  44. GRB971214: Optical Observations and Calibrations
  45. Optical Observations of GRB 971214 at Keck
  46. GRB 971214: USNOFS Observations Summary

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Download all Circulars as a .tar.gz archive:
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