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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"

21 results found.

  1. GRB 191031D: XMM-Newton upper limit
  2. GRB 191031D: CALET Gamma-Ray Burst Monitor detection
  3. GRB 191031D: Chandra upper limit
  4. GRB 191031D: Zwicky Transient Facility Follow-Up of a Swift Short GRB (Trigger 594249816/191031891)
  5. Konus-Wind observation of GRB 191031D: correction to GCN 26126
  6. GRB 191031D: Gemini optical upper limit
  7. GRB 191031D: MMT Binospec Optical Upper Limit
  8. GRB 191031D: Swift-BAT refined analysis
  9. GRB 191031D: AstroSat CZTI detection
  10. GRB 191031D: Swift/UVOT Upper Limits
  11. Konus-Wind observation of GRB 191031D
  12. GRB 191031D: MITSuME Akeno optical upper limits
  13. GRB 191031D: Swift-XRT refined Analysis
  14. GRB 191031D: AGILE/MCAL observations
  15. GRB 191031D: COATLI Optical Observations
  16. GRB 191031D: RATIR Optical and NIR Observations
  17. GRB 191031D: VLA 9.8 GHz upper limit
  18. GRB 191031D: Fermi GBM detection
  19. GRB 191031D: Enhanced Swift-XRT position
  20. Correction in name: GRB 191031D (not GRB 191031C)
  21. GRB 191031D: Swift detection of a short hard burst

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