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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"

14831 results found.

  1. GRB061126: update on the Swift-XRT afterglow light curve
  2. GRB 061202: Swift detection of a burst
  3. GRB 061201: Swift detection of a short hard burst
  4. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  5. GRB 061121: ATCA & WSRT Radio Observations
  6. GRB 061126: Swift/UVOT Observations
  7. GRB 061126: Early Detection of the IR Afterglow
  8. GRB 061126: Faulkes Telescope North Optical Observations
  9. GRB 061126: Swift/UVOT Afterglow Detection
  10. GRB 061126: Swift detection of a burst
  11. GRB 061121: ART detection in Ic
  12. Radio detection of GRB 061121
  13. GRB 061121: Faulkes Telescope North Optical Observation
  14. GRB061121: Spectroscopic Redshift
  15. GRB 061121: Swift detection of a bright burst with an optical counterpart
  16. GRB 060111B: Swift UVOT Refined Magnitudes
  17. GRB 061110A - VLT tentative redshift
  18. GRB 061110A: Swift XRT refined analysis
  19. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  20. GRB 061110B: Swift detection of a burst
  21. GRB 061110: Swift detection of a burst
  22. GRB061110A - Optical Non-detection
  23. GRB 061109: Swift detection of a possible burst
  24. GRB 061028: Optical R passband observations
  25. GRB 061102B: Swift detection of a possible burst
  26. GRB 061102: Swift detection of a burst
  27. GRB 061028: VLA Observation
  28. GRB061028: XRT refined analysis
  29. GRB 061028: Swift detection of a burst
  30. GRB 061027, Swift refined analysis of a possible burst
  31. GRB 061027: Swift detection of a possible burst
  32. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  33. GRB 061021: Swift detection of a burst
  34. GRB 061019: SMARTS afterglow confirmation
  35. GRB 061019: Swift-BAT detection of a burst
  36. GRB061007: Swift UVOT followup observations
  37. GRB 061007: Swift-BAT refined analysis
  38. GRB 061007: Swift detection of a burst with an optical counterpart
  39. GRB 061007: ROTSE-III Detection of Optical Counterpart
  40. GRB 061006: Swift detection of a burst
  41. GRB 061004: Swift detection of a burst
  42. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  43. GRB 060928: Swift observations
  44. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  45. GRB 061002: Swift detection of a burst
  46. GRB 060908: Detection of a possible host
  47. GRB 060923A: Probable host galaxy in the R-band
  48. GRB 060807: Detection of a possible host galaxy
  49. GRB 060929: Swift detection of a burst
  50. GRB 060729: An update on the late-time Swift observations
  51. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  52. GRB 060927: Early color
  53. GRB060926: improved redshift
  54. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  55. GRB 060927: Swift detection of a burst
  56. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  57. GRB 060926: Swift detection of a burst
  58. GRB 060923C: VLA Observation
  59. GRB 060923C: Swift detection of a burst
  60. GRB 060923B: Swift detection of a burst
  61. GRB 060923: Swift detection of a burst
  62. Swift detection of IGR J17497-2821 (trigger 230504)
  63. GRB 060919: Swift detection of a burst
  64. GRB 060912A: VLA Observation
  65. GRB 060912: Swift detection of a burst with an optical afterglow
  66. VLA observations of GRB 060908
  67. GRB 060908: PROMPT Detection of a Bright Counterpart
  68. GRB 060908: Swift detection of a burst with a bright optical counterpart
  69. GRB 060906: KAIT observations
  70. GRB 060906: Swift detection of a probable burst
  71. GRB 060904A: Swift-XRT refined analysis
  72. GRB060904B: Watcher observations
  73. GRB 060904B: Swift detection of a burst with optical counterpart
  74. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  75. GRB 060904: Swift detection of a bright burst
  76. GRB 060901: SMARTS optical/IR observations update
  77. GRB 060901: SMARTS optical/IR observations
  78. GRB 060901: Watcher observations
  79. GRB 060604: VLA Observation
  80. GRB 060605: VLA Observation
  81. GRB 060707: VLA observation
  82. GRB 060825: VLA observations
  83. GRB 060826(?): Swift detection of a possible burst
  84. GRB 060825: Swift detection of a burst
  85. Radio observations of GRB 060719
  86. GRB 060814: Swift detection of a bright burst
  87. GRB 060813: Swift detection of a burst
  88. Image of the dust-scattering halo around SGR 1806-20
  89. Second VLA limit on new radio point source in SGR 1806-20
  90. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  91. GRB060807: Possible Highly Significant X-ray Emission Lines
  92. GRB 060805B: optical observation at Sierra Nevada
  93. VLA Upper Limit on Outburst of SGR 1806-20
  94. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  95. GRB 060807: Swift detection of a burst
  96. GRB 060805: Swift detection of a burst
  97. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  98. GRB 060801: optical observations at Hanle and Calar Alto
  99. GRB 060801: Swift detection of a short burst
  100. GRB 060218 / SN 2006aj Nebular Spectrum

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