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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').

18344 results found.

  1. GRB 050117: Optical observation
  2. GRB050117: Refined XRT position
  3. GRB050117: MASTER optical observations
  4. MASTER:GRB050117 SWIFT
  5. GRB050117: Swift-BAT detection of a long multi-peaked burst
  6. GRB050117: Swift XRT Position
  7. SGR1806-20: Swift-BAT observations of two additional bursts
  8. SGR 1806-20, RHESSI observations of the 041227 giant flare
  9. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  10. GRB 041217: Optical observations
  11. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  12. GRB041228: ROTSE-III Optical Observations
  13. GRB041228: Swift-BAT detection of a burst
  14. GRB041219; RXTE ASM Observations
  15. NIR Observations of GRB 041219
  16. GRB041226: ROTSE-III Optical Observations
  17. GRB041226: Swift-BAT detection of a burst
  18. GRB041223: decay of the afterglow
  19. GRB041224: ROTSE-III Optical Observations
  20. GRB 041223: XRT afterglow spectrum and light curve
  21. GRB 041223 Fluence measured by Swift-BAT
  22. GRB041224: Swift-BAT detection of a soft burst
  23. GRB041223: optical and NIR observations with REM
  24. Swift-BAT Time History of GRB041219
  25. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  26. GRB041223: ROTSE-III Optical Observations
  27. GRB041223: Swift-BAT detection of a bright long burst
  28. GRB041220: Swift-BAT burst
  29. GRB 041219 Optical Observations
  30. GRB041219c: Third Burst in One Day from Swift-BAT
  31. GRB041219b: A Swift-BAT burst
  32. Swift-BAT detection of the bright long burst GRB041219
  33. GRB041217: optical limit 30 min after GRB
  34. GRB041217: Optical Observations
  35. GRB041217: NIR and optical observations with REM
  36. GRB041217: P60 Optical Observations
  37. GRB041217: Infrared Observations
  38. GRB041217: The First GRB Located On-Board Swift
  39. GRB040916: Optical observations
  40. GRB040422: optical and NIR observations at the VLT
  41. GRB040223, improved XMM position
  42. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  43. GRB 021004: VRI observations at TNG: possible break
  44. GRB 021004: WC wind?

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