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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"

3139 results found.

  1. GRB 020625, optical observations
  2. GRB 020317 : KISO Optical Observations
  3. GRB 020305: Candidate optical afterglow
  4. GRB020305, optical observations
  5. GRB020305 (=H1939): Localization of a GRB by HETE
  6. IPN Upper Limits to a GRB Associated With SN2002ap
  7. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  8. GRB 011130: Optical Observations of Chandra Sources
  9. GRB011130 (XRF011130) Chandra Observations
  10. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  11. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  12. SGR1806-20: Localization by HETE
  13. GRB010222: possible optical counterpart
  14. IPN triangulation of GRB 001004
  15. GRB000926 K'-band Observation
  16. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  17. IPN localization of GRB000801
  18. IPN localization of GRB000730
  19. GRB000623
  20. GRB000615, R-band photometry
  21. BeppoSAX X-ray transient/possible GRB000608
  22. GRB 000408, optical observations
  23. IPN annulus for GRB000115
  24. Single IPN error box for GRB991229
  25. IPN error boxes for GRB991229
  26. Single IPN error box for GRB991221
  27. IPN error boxes for GRB991221
  28. GRB 991216 RXTE ASM Observations
  29. IPN localization of GRB990704
  30. GRB990510: X-ray afterglow
  31. GRB990510 optical observations
  32. GRB 990506, optical observations
  33. GRB 990506, optical observations
  34. GRB 981220 Optical observations
  35. GRB981226, sub-millimeter observations
  36. Optical Observations of GRB981226
  37. GRB 981220:Optical Observations
  38. GRB 981226 - Infrared Observations
  39. GRB 971214: USNOFS Observations Summary

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Download all Circulars as a .tar.gz archive (updated once a day):
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