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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"

5039 results found.

  1. GRB990123 observations
  2. GRB 990123: Reduced HST Images
  3. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  4. GRB 990123: New Constraints on Possible Foreground Galaxies
  5. GRB990123 Optical Observations
  6. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  7. GRB 990123: Continued Radio Observations
  8. Search for Potential Images of GRB 990123
  9. GRB990123, Optical BVRI Observations
  10. GRB 990123: near-infrared observations.
  11. GRB990123: NIR Observation
  12. "GRB 990123: New BV Observations"
  13. GRB990123 Optical Observations
  14. GRB981220
  15. GRB 981220 Optical observations
  16. GRB 981220 and GRB 981226, optical observations
  17. GRB 981226 optical observations
  18. GRB981220 B, R and I band observations
  19. GRB 981226 - Infrared Observations
  20. GRB 981220
  21. GRB981220 I-band Observations
  22. GRB980425 Optical Follow-up
  23. GRB980613 Optical Observations
  24. SGR 1627-41
  25. GRB980519 optical observations
  26. GRB 980519 Optical Observations
  27. GRB 980425 Brightness Temperature
  28. GRB980329, Fading IR counterpart to radio source
  29. Near-IR follow-up on GRB 971227
  30. GRB971214: Keck R & I-band Observations
  31. Optical Observations of the GRB 971227 field
  32. GRB971227: Plaskett R-band observations
  33. GRB971227: Further CAHA R-band images
  34. GRB 971214: KPNO Optical Observations
  35. Optical Observations of GRB 971214 at Keck
  36. GRB 971214: Optical Observations
  37. GRB 971024: Refined analysis by USNOFS Observations
  38. GRB 971024: USNO Observations
  39. GRB 970228: Keck/LRIS Optical Observations

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Download all Circulars as a .tar.gz archive:
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