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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"

25 results found.

  1. EP250404a: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  2. GRB 240727A: VIRT Optical Upper Limit
  3. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  4. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  5. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  6. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  7. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  8. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  9. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  10. GRB240204A: VIRT optical upper limit
  11. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  12. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  13. GRB 231216A: 10.4 m GTC optical upper limit
  14. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  15. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  16. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  17. GRB231111A: Optical follow-up observations with Mephisto
  18. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  19. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  20. GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
  21. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  22. GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
  23. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  24. GRB 230427A: Osservatorio Astronomico Nastro verde upper limit
  25. GRB 230414B: Osservatorio Astronomico Nastro Verde - Sorrento: optical observations

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