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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"

18473 results found.

  1. short/hard GRB 050202, optical observations
  2. GRB 050128: Radio observations
  3. Further analysis of the short Swift-BAT GRB 050202
  4. GRB 050202: Second epoch radio observations
  5. GRB050202: Radio Observations
  6. GRB 050202: Short burst detected by Swift-BAT
  7. SGR1806-20: Swift-BAT detection of a large normal burst
  8. GRB050128: Faulkes Telescope South observations
  9. GRB050128,optical observations
  10. GRB050126: Updated Swift XRT Position
  11. GRB 050126: Radio Observations
  12. GRB050128 Swift-BAT observations
  13. GRB 050128: Swift XRT prompt afterglow position
  14. GRB 050124: K-band afterglow observations
  15. GRB050126: MASTER optical limit for KECK OT
  16. GRB050126: Burst Parameters Measured by BAT
  17. GRB050126: MASTER optical observations
  18. GRB 050126: Prompt XRT detection and localization
  19. GRB050124: No Swift UVOT Detection of Afterglow Emission
  20. GRB 050117a: Radio Observations
  21. GRB050124,optical observation
  22. GRB050124: Updated Swift XRT Position and Fluxes
  23. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  24. GRB050124: Refined BAT position, spectral and fluence information
  25. GRB050124: Swift-BAT position of a double-peaked burst
  26. GRB050117a: Radio Observations
  27. GRB050117a: Refined analysis
  28. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  29. GRB050117b: Swift-BAT detection of a weak burst
  30. GRB050117: optical observation
  31. GRB 050117, I-band observations
  32. GRB 050117: Optical observation
  33. GRB050117: Refined XRT position
  34. GRB050117: MASTER optical observations
  35. MASTER:GRB050117 SWIFT
  36. GRB050117: Swift-BAT detection of a long multi-peaked burst
  37. GRB050117: Swift XRT Position
  38. SGR1806-20: Swift-BAT observations of two additional bursts
  39. SGR 1806-20, RHESSI observations of the 041227 giant flare
  40. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  41. GRB 041217: Optical observations
  42. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  43. GRB041228: ROTSE-III Optical Observations
  44. GRB041228: Swift-BAT detection of a burst
  45. GRB041219; RXTE ASM Observations
  46. NIR Observations of GRB 041219
  47. GRB041226: ROTSE-III Optical Observations
  48. GRB041226: Swift-BAT detection of a burst
  49. GRB041223: decay of the afterglow
  50. GRB041224: ROTSE-III Optical Observations
  51. GRB 041223: XRT afterglow spectrum and light curve
  52. GRB 041223 Fluence measured by Swift-BAT
  53. GRB041224: Swift-BAT detection of a soft burst
  54. GRB041223: optical and NIR observations with REM
  55. Swift-BAT Time History of GRB041219
  56. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  57. GRB041223: ROTSE-III Optical Observations
  58. GRB041223: Swift-BAT detection of a bright long burst
  59. GRB041220: Swift-BAT burst
  60. GRB 041219 Optical Observations
  61. GRB041219c: Third Burst in One Day from Swift-BAT
  62. GRB041219b: A Swift-BAT burst
  63. Swift-BAT detection of the bright long burst GRB041219
  64. GRB041217: optical limit 30 min after GRB
  65. GRB041217: Optical Observations
  66. GRB041217: NIR and optical observations with REM
  67. GRB041217: P60 Optical Observations
  68. GRB041217: Infrared Observations
  69. GRB041217: The First GRB Located On-Board Swift
  70. GRB040916: Optical observations
  71. GRB040422: optical and NIR observations at the VLT
  72. GRB040223, improved XMM position
  73. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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