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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"

20947 results found.

  1. GRB980329 near-IR observations
  2. GRB980329 near-IR observations
  3. GRB980329 optical observations
  4. GRB980329 infrared observations
  5. GRB980329 optical observations
  6. GRB980326 optical observations
  7. GRB980329 optical observations
  8. GRB980329 VLA observations
  9. GRB980329 near IR observations
  10. GRB980329 optical observations
  11. GRB980329 optical observations
  12. GRB980329 optical observations
  13. GRB980326 optical observations
  14. GRB980326 optical observations
  15. GRB980326 optical observations
  16. GRB980326 optical observations
  17. GRB970508 SAO RAS optical observations
  18. Optical Observations of GRB 970508
  19. GRB 971214: Redshift from Keck Observations
  20. GRB971214: Keck R & I-band Observations
  21. GRB 971227: Optical Observations
  22. Optical Observations of the GRB 971227 field
  23. Optical Observations on GRB 971227
  24. GRB971227: Plaskett R-band observations
  25. Optical Observations for GRB 971227
  26. GRB971227: Further CAHA R-band images
  27. GRB971227: LOTIS observations
  28. GRB 971227: CAHA R-band images
  29. GRB 971227: Optical observations
  30. GRB971214: Optical Observations and Calibrations
  31. Sub-millimeter Observations of GRB 971214 at the JCMT
  32. GRB 971214: EUVE Observations
  33. GRB 971214: Redshift from Keck Optical Observations
  34. GRB 971214: Redshift from Keck Optical Observations
  35. GRB 971214: Apache Point Observatory Optical Observations
  36. GRB 971214: KPNO Optical Observations
  37. Optical Observations of GRB 971214 at Keck
  38. GRB 971214: Optical Observations
  39. Radio Observations of GRB 971214 at the VLA
  40. GRB 971214: USNOFS Observations Summary
  41. GRB 971024: KPNO Optical Observations Summary
  42. GRB 971024: Refined analysis by USNOFS Observations
  43. GRB 971024: KPNO Optical Observations
  44. GRB 971024: USNO Observations
  45. RXTE Observations of SGR 1814-13
  46. GRB 970828: Palomar Observations
  47. GRB 970228: Keck/LRIS Optical Observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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