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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"

40 results found.

  1. GRB 100814A: Submm observations from APEX
  2. GRB 100418A: late time optical observations
  3. Radio detection of GRB100418a with ATCA
  4. GRB 100418A: Maidanak optical observations
  5. GRB 100418A: Subaru late-time optical imaging and spectroscopy
  6. GRB 100418A: CrAO optical observations
  7. GRB 100418A: Keck imaging
  8. GRB 100418A: RTT150 optical observations
  9. GRB 100418A: Flattening of the Swift/UVOT Optical Light Curve
  10. GRB 100418A: RTT150 optical observations
  11. GRB 100418A: Terskol optical observations
  12. GRB 100418A: ROVOR optical measurements at 35 hours
  13. GRB 100418A: Possible Evidence for a Supernova
  14. Radio afterglow detection of GRB 100418A with the EVLA
  15. GRB 100418A: Continued PAIRITEL NIR Observations
  16. GRB 100418A: WSRT Radio Detection
  17. GRB100418A: REM possible afterglow detection
  18. GRB 100418A: Continuing Swift/UVOT Observations
  19. GRB 100418A: further GROND observations and light curve fit
  20. GRB 100418A: RTT150 optical observations
  21. GRB 100418A: SARA second epoch
  22. GRB 100418A: RTT150 observations during the optical afterglow maximum
  23. GRB 100418A: optical observations
  24. GRB 100418A: MASTER-Net optical observations
  25. GRB 100418A: VLT optical observations
  26. GRB 100418A: SMA submm detection
  27. GRB 100418A PAIRITEL NIR Observations
  28. GRB 100418A: ROVOR optical afterglow detection
  29. GRB 100418A: Swift/UVOT Observations
  30. GRB 100418A: Gemini-N redshift confirmation
  31. GRB 100418A: Swift-XRT Refined Analysis
  32. GRB 100418A: host galaxy detection in the SDSS
  33. GRB100418A: VLT/X-shooter redshift and photometry
  34. GRB 100418A: SARA observations
  35. GRB 100418A: GROND observations; missing author list added
  36. GRB 100418A: GROND observations
  37. GRB 100418A: Swift-BAT refined analysis
  38. GRB 100418A: Enhanced Swift-XRT position
  39. GRB 100418A: ROTSE-III Optical Limits
  40. GRB 100418A: Swift detection of a burst with a possible optical afterglow

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