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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"

29 results found.

  1. GRB 241026A: radio detection with the VLA
  2. GRB 241026A: VIRT Optical Upper Limit
  3. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  4. GRB 241026A: SAO RAS optical observations
  5. GRB 241026A: Swift-BAT refined analysis
  6. GRB 241026A: LBT optical observations
  7. GRB 241026A: SAO RAS optical observations
  8. GRB 241026A: Swift/UVOT Upper Limits
  9. GRB 241026A: the 100th GRB detected by GRBAlpha
  10. GRB 241026A: TNOT optical counterpart detection
  11. GRB 241026A: LBT redshift confirmation
  12. GRB 241026A: GECAM detection
  13. GRB 241026A: BTA and Zeiss-1000 optical observations
  14. GRB 241026A: SVOM/GRM observation
  15. GRB 241026A: GROWTH-India Telescope optical observations
  16. GRB 241026A Fermi GBM Analysis
  17. GRB 241026A: BTA redshift identification of z = 2.79
  18. GRB 241026A: J-band observations with WINTER
  19. GRB 241026A: Las Cumbres optical detection
  20. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  21. GRB 241026A: Swift-XRT refined Analysis
  22. GRB 241026A: Enhanced Swift-XRT position
  23. GRB 241026A: KAIT optical observations
  24. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  25. GRB 241026A: SAO RAS observations of possible optical afterglow
  26. Fermi GRB 241026A: Global MASTER-Net observations report
  27. GRB 241026A: Prompt enhanced Swift-XRT position
  28. GRB 241026A: Swift detection of a burst
  29. GRB 241026A: Fermi GBM Final Real-time Localization

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