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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"

1145 results found.

  1. GRB 100418A: Subaru late-time optical imaging and spectroscopy
  2. GRB 090709A: evidence for a very red afterglow at low z
  3. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  4. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  5. GRB 090709A: Subaru NIR observation
  6. GRB 090417B: Subaru NIR Observations
  7. GRB 090118: Subaru NIR Observation
  8. GRB 080325: Subaru detection of NIR afterglow candidate
  9. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  10. GRB 071021: Subaru NIR observation
  11. GROND upper limits of GRB 070521
  12. GRB 070521: Subaru observations and possible host detection
  13. GRB 070520A: Subaru Observations
  14. GRB 060904A: Subaru NIR observation
  15. GRB 060512: Subaru NIR observation
  16. GRB 060206: near-infrared observations (JK' imaging)
  17. GRB 060206: Subaru/FOCAS optical spectroscopy
  18. GRB 050904: Subaru Optical Spectroscopy
  19. Subaru Observations of GRB050724
  20. GRB 050509B and short GRB-SN association? (corrected)
  21. GRB 050509B and short GRB-SN association?
  22. GRB 050509B: Subaru Optical Observations
  23. GRB 050412: Subaru observations
  24. GRB 050408: Subaru Observations
  25. GRB 040916: Afterglow Color at Early Times
  26. GRB 040924: detection of possible host galaxy by Subaru
  27. GRB 040924: NIR finding chart
  28. GRB 040924: Subaru NIR observation
  29. XRF040916: continuing decay of OT
  30. XRF040916: Optical Transient Candidate by Subaru
  31. GRB 031220: Subaru observation
  32. XRF 030723: Subaru Optical Observations
  33. GRB030913: Subaru Optical Observations
  34. GRB030329: Subaru Optical Spectroscopy
  35. GRB030226: optical observations and refined redshift
  36. GRB 030226 Optical Spectra and R,I,z' Imaging
  37. Fading Optical Source in the Field of GRB020531
  38. GRB020331 NIR observation at KPNO (re-submission)
  39. GRB02033 NIR observation at KPNO
  40. GRB020305: Subaru Optical Observations
  41. GRB011019: Subaru Optical Observations
  42. GRB 010222
  43. GRB000926 K'-band Observation
  44. GRB000301C, near-infrared observations (JHK' imaging)
  45. GRB000301C, near-infrared observations (JHK' photometry)

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