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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"

22 results found.

  1. GRB 201020B: Assy, Koshka, Mondy and Maidanak optical observations
  2. GRB 201020B: 1.3m DFOT continued optical follow-up observations
  3. GRB 201020B: HCT and GIT continued optical follow-up observations
  4. GRB 201020B: follow-up observations with Savelli Telescope
  5. GRB 201020B: 1.3m DFOT optical observations
  6. GRB 201020B: follow-up observations at Konkoly
  7. GRB 201020B: continued Mondy optical observations
  8. GRB 201020B: Redshift from GTC/OSIRIS
  9. GRB 201020B: GROWTH-India Telescope optical observations
  10. GRB 201020B: Konkoly Obs. optical detection
  11. GRB 201020B: Swift/UVOT Detection
  12. GRB 201020B: Swift-XRT afterglow detection
  13. GRB 201020B: Mondy optical observations
  14. Konus-Wind detection of GRB 201020B
  15. GRB 201020B: Swift ToO observations
  16. GRB 201020B: Nanshan/NEXT optical afterglow confirmation
  17. GRB 201020B: MASTER bright optical afterglow detection
  18. GRB 201020B: Fermi-LAT detection
  19. GRB 201020B: AGILE detection
  20. GRB 201020B: Fermi GBM detection
  21. Fermi GRB 201020B: Global MASTER-Net observations report
  22. GRB 201020B: Fermi GBM Final Real-time Localization

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Download all Circulars as a .tar.gz archive:
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