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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"

23 results found.

  1. GRB 251129A: redshift correction and SN detection at z = 0.505 with GTC
  2. GRB 251129A / EP251129a: VLA detection of a radio counterpart
  3. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  4. GRB 251129A: e-MERLIN C-band observations
  5. GRB 251129A/EP251129a : SVOM/ECLAIRs refined analysis
  6. GRB 251129A / EP251129a: SVOM/VT optical color bluer
  7. GRB251129A/EP251129a: Swift UVOT detection
  8. EP251129a/GRB 251129A: NOWT Detection
  9. EP251129a/GRB 251129A: EP-FXT follow-up observations
  10. GRB 251129A / EP251129a: GTC/OSIRIS+ spectroscopic redshift z = 1.460
  11. GRB 251129A / EP251129a: OSN and CAHA optical follow-up
  12. GRB 251129A / EP251129a: SAO RAS optical observations
  13. SVOM GRB 251129A : MASTER optical counterpart detection
  14. GRB 251129A: Swift-XRT afterglow detection
  15. GRB 251129A: Swift ToO observations
  16. GRB 251129A / EP251129a: SVOM/VT optical fading
  17. GRB 251129A: Optical Observations via Virtual Telescope Project, Italy
  18. EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
  19. GRB 251129A: Correction to the position of the optical counterpar
  20. GRB 251129A: SVOM/VT optical counterpart confirmation with VHF data
  21. GRB 251129A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  22. GRB 251129A: SVOM detection of a burst
  23. GRB 251129A: SVOM detection of a burst

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Download all Circulars as a .tar.gz archive:
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