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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"

2722 results found.

  1. GRB000226 [IPN Position]
  2. IPN localization of GRB991226
  3. GRB991216 Optical and infrared observations of Beethoven Burst
  4. GRB991216 ('Beethoven Burst') B, R, and K Observations
  5. IPN localization of GRB991208
  6. IPN localization of GRB991105
  7. IPN localization of GRB991014 - CORRECTION
  8. IPN localization of GRB991014
  9. IPN error box for GRB990915 (=BATSE 7766)
  10. GRB 990704, optical observations
  11. GRB 990506, optical observations from +1 to +3 hours
  12. GRB 990123: BVRI standards in the field
  13. GRB990123 Optical Observations
  14. GRB990123, early optical counterpart detection
  15. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  16. GRB981226, BeppoSAX Christmas GRB
  17. GRB981220 I-band Observations
  18. BATSE on-board GRB trigger change
  19. GRB980326 IPN annulus
  20. GRB980329 IPN annulus
  21. GRB 971024: Refined analysis by USNOFS Observations
  22. GRB 971024: USNO Observations

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Download all Circulars as a .tar.gz archive:
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