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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 210704A: Zeiss-1000/SAO-RAS optical observations
  2. GRB 210704A: classification as long GRB and redshift estimating
  3. GRB 210704A: Lowell Discovery Telescope Optical Observations
  4. GRB 210704A: Continued Gemini-North NIR K-band Detections
  5. GRB 210704A: INTEGRAL observations
  6. GRB 210704A: NOT optical observations and color change
  7. GRB210704A: Gemini near-infrared upper limits
  8. GRB 210704A: Assy optical afterglow upper limit
  9. GRB 210704A: OSIRIS/GTC Observations and Archival Detection of the Possible Host Galaxy
  10. GRB 210704A: Gemini-North Infrared Source Detection
  11. GRB 210704A: further TNG optical observations
  12. GRB 210704A: CAHA 2.2m telescope optical limit
  13. GRB 210704A: OAJ T80 multi-color detections
  14. GRB 210704A: OSIRIS/GTC spectroscopy
  15. GRB 210704A: CAHA 2.2m Afterglow Detection
  16. GRB 210704A: RATIR optical upper limits
  17. GRB 210704A: Swift/UVOT Upper Limits
  18. Konus-Wind detection of GRB 210704A
  19. GRB 210704A: TNG detection of the optical afterglow candidate
  20. GRB 210704A: Assy optical afterglow candidate
  21. GRB 210704A: DDOTI upper limit
  22. GRB 210704A: possible local hosts
  23. GRB 210704A: Fermi GBM detection
  24. GRB 210704A: Swift-XRT afterglow detection
  25. GRB 210704A: AstroSat CZTI detection
  26. GRB 210704A: Fermi-LAT detection
  27. GRB 210704A: Swift ToO observations
  28. GRB 210704A: AGILE/MCAL detection
  29. GRB 210704A: BALROG localization (Fermi Trigger 647120009 / GRB 210704815)

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