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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"

26499 results found.

  1. GRB 061126 : SDSS Pre-Burst Observations
  2. GRB 061126: Swift-XRT refined analysis
  3. GRB 061126: Swift/UVOT Observations
  4. GRB 061126: Early Detection of the IR Afterglow
  5. GRB 061126: Faulkes Telescope North Optical Observations
  6. GRB 061122: Candidate Optical Afterglow
  7. GRB061122: Swift/UVOT Optical Observations
  8. GRB061121: P60 Observations
  9. Radio detection of GRB 061121
  10. GRB061122: Swift-XRT position
  11. Konus-Wind observation of GRB 061122
  12. RHESSI Spectrum of GRB061121
  13. Konus-Wind and Konus-A observations of GRB 061121
  14. Swift-BAT trigger 239987 is not a GRB
  15. GRB 061122A: a long GRB detected by INTEGRAL
  16. GRB 061121: Swift/UVOT Observations
  17. GRB 061121: Swift-XRT Team Refined Analysis
  18. GRB061121, optical observation
  19. GRB 061121: Optical observation at the KANATA 1.5m telescope
  20. GRB 061121: Faulkes Telescope North Optical Observation
  21. GRB 061121: Swift detection of a bright burst with an optical counterpart
  22. GRB 060605: NIR Observations
  23. GRB 050915B: optical afterglow
  24. GRB 061110B: NIR Observations
  25. Swift/UVOT Upper Limits for GRB061110b
  26. Swift/UVOT Upper Limits for GRB061110a
  27. GRB 061110A - VLT tentative redshift
  28. GRB 061110B: Swift XRT refined analysis
  29. GRB061110B: Optical observations at Crni Vrh
  30. GRB 061110A: Swift XRT refined analysis
  31. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  32. GRB 061110A, Swift-BAT refined analysis
  33. GRB 061110B: TAROT Calern observatory optical observations
  34. GRB 061110B: Swift detection of a burst
  35. GRB 061110: Candidate confirmed
  36. GRB 061110: ROTSE-III Optical Limits
  37. GRB 061110: Swift detection of a burst
  38. GRB061110A - Optical Non-detection
  39. GRB 061109: TAROT Calern observatory optical observations
  40. GRB061028: MAGIC telescope GeV observation
  41. GRB 061027: TAROT La Silla observatory optical observations
  42. GRB061019: second epoch CrAO observations
  43. GRB 061028: Swift/XRT Astrometry Correction
  44. GRB 061102: Swift/UVOT Magnitude Upper Limits
  45. GRB 061102, XRT refined analysis
  46. GRB 061004: Further VLT/NTT observations
  47. GRB061102B: Super-LOTIS observations
  48. GRB 061028: Optical R passband observations
  49. GRB 061102B: Swift detection of a possible burst
  50. GRB 061102: Swift detection of a burst
  51. GRB 061028: VLA Observation
  52. GRB 061004: Swift/XRT Astrometry Correction
  53. GRB 060801: Swift/XRT Astrometry Correction
  54. GRB 061028: Futher P200 Observations
  55. GRB 061028: P200 Observations
  56. GRB 061028: SARA upper limit
  57. GRB 061028: z band imaging
  58. GRB061028: XRT refined analysis
  59. GRB 061028: Swift/UVOT Observations
  60. GRB 061028: TAROT Calern observatory optical observations
  61. GRB 061028: Swift detection of a burst
  62. GRB 061027, Swift refined analysis of a possible burst
  63. GRB 061027: Swift detection of a possible burst
  64. GRB061025: Swift XRT refined analysis
  65. GRB061025: Swift/UVOT observations
  66. GRB 061025: REM observations
  67. GRB061025: Swift XRT position
  68. GRB 061025: ROTSE-III Optical Limits
  69. GRB 061025: a long GRB detected by INTEGRAL
  70. Konus-Wind observation of GRB 061021
  71. GRB 061021: Swift-XRT refined analysis
  72. GRB 061021: Swift/UVOT Observation
  73. GRB 061021: Swift detection of a burst
  74. GRB 061019: SARA upper limit
  75. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  76. GRB 060930: MARGE Optical Limits
  77. GRB 061019: Swift/UVOT upper limit
  78. GRB061019: Swift XRT refined analysis
  79. GRB 061019: TAROT La Silla observatory optical observations
  80. GRB 061019: REM K-band candidate afterglow
  81. GRB 061019: Swift-BAT detection of a burst
  82. GRB 061007: RHESSI Spectral Fit
  83. GRB 061006: astrometry-corrected XRT position
  84. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  85. GRB061007: Swift UVOT followup observations
  86. GRB 061006: optical afterglow
  87. GRB 061006 : Suzaku/WAM observation of the prompt emission
  88. GRB 061007: OA fading and VLT redshift
  89. GRB 061007: Correction to GCN 5712
  90. GRB 061007: Swift XRT refined analysis
  91. GRB 061006: Swift/UVOT optical observations
  92. Konus-Wind observation of the short hard GRB 061006
  93. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  94. GRB 061007: Swift detection of a burst with an optical counterpart
  95. GRB 061006: VLT observation
  96. GRB 061006: Swift-XRT Team Refined Analysis
  97. GRB 060930: near-IR afterglow candidate retraction
  98. GRB 061004: Optical afterglow candidate and redshift
  99. GRB 061004: Swift-XRT Team Refined Analysis
  100. GRB 061004: Swift detection of a burst

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