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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"
  1. GRB 060904: TAROT optical observations
  2. GRB 060904B: Swift detection of a burst with optical counterpart
  3. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  4. GRB060904 - SDSS Pre-Burst Observations
  5. GRB 060904: Swift detection of a bright burst
  6. GRB060901: Optical observations
  7. 060901: Swift UVOT followup observations
  8. GRB 060901: pseudo-z from spectral parameters of the prompt
  9. Konus-Wind observation of GRB 060901
  10. GRB 060901: SMARTS optical/IR observations update
  11. GRB 060901: Swift/XRT Refined Analysis
  12. GRB 060901: SMARTS optical/IR observations
  13. GRB 060901: Swift/XRT Position
  14. GRB 060901: further INTEGRAL results
  15. GRB 060901: Watcher observations
  16. GRB 060901: a long GRB detected by INTEGRAL
  17. Two bright bursts from SGR 1806-20 detected with IBAS
  18. GRB 060605, observations using an Integral Field Unit
  19. GRB 060604: VLA Observation
  20. GRB 060814: Suzaku/WAM observation of the prompt emission
  21. GRB 060605: VLA Observation
  22. GRB 060707: VLA observation
  23. GRB 060825: VLA observations
  24. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  25. Swift-BAT trigger 226614 is not a GRB
  26. GRB060826 - SDSS Pre-Burst Observations
  27. GRB 060826(?): Swift detection of a possible burst
  28. GRB 060825: XRT Team Refined Analysis
  29. GRB 060825: Swift-BAT Refined Analysis
  30. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  31. GRB060825: Liverpool Telescope optical observations
  32. GRB 060825: TNG optical observations
  33. GRB 060825: TAROT optical observations
  34. GRB 060825: P60 Observations
  35. GRB060825: BOOTES-IR optical observations
  36. GRB 060825: Swift detection of a burst
  37. GRB060801: host galaxy redshift
  38. GRB060729: analysis of XMM-Newton observation
  39. GRB 060814: pseudo-z from spectral parameters of the prompt
  40. IBAS Alerts No 3429 and 3430: not GRBs
  41. Radio observations of GRB 060719
  42. GRB 060729, SMARTS optical/IR observations
  43. GRB060814: Break in the XRT light curve
  44. GRB060813: Break in the XRT light curve
  45. GRB 060813: A long, bright GRB detected with Suzaku WAM
  46. GRB 060814: Confirmation of IR afterglow
  47. Konus-Wind observation of GRB 060814
  48. GRB 060814: Refined analysis of the Swift-BAT burst
  49. GRB 060814: P60 Observations
  50. GRB 060814: P200 NIR Observations
  51. GRB 060814: source inside revised XRT error box
  52. GRB 060814: Possible IR counterpart
  53. GRB060805B: optical observations
  54. GRB060814: Swift/UVOT upper limits
  55. GRB 060813: pseudo-z from spectral parameters of the prompt
  56. GRB 060814: Swift XRT refined analysis
  57. GRB 060814: VLT optical limits
  58. GRB 060814 - SDSS Pre-Burst Observations
  59. GRB 060814: TAROT optical observations
  60. GRB 060814: Swift detection of a bright burst
  61. Konus-Wind observation of GRB 060813
  62. GRB060813: Swift/UVOT upper limits
  63. GRB 060813: Swift XRT refined analysis
  64. GRB 060813: Refined analysis of the Swift-BAT burst
  65. GRB 060813: Swift detection of a burst
  66. GRB051109B: Late-time Radio Observations
  67. Image of the dust-scattering halo around SGR 1806-20
  68. Second VLA limit on new radio point source in SGR 1806-20
  69. A dust-scattering halo detected around SGR 1806-20
  70. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  71. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  72. GRB060807: Possible Highly Significant X-ray Emission Lines
  73. GRB060714: optical observations
  74. IBAS Alert n. 3422: not a GRB
  75. GRB 060729: An update on the Swift XRT and UVOT observations
  76. GRB060717: optical observations
  77. GRB060807: Optical limiting magnitudes
  78. GRB 060805B: optical observation at Sierra Nevada
  79. GRB 060805B: XRT Team Analysis
  80. VLA Upper Limit on Outburst of SGR 1806-20
  81. GRB060806 is similar to previous activity of SGR1806-20
  82. GRB 060807: UVOT Upper limits
  83. GRB 060807: afterglow confirmation
  84. GRB 060807: XRT Team refined analysis
  85. GRB 060807: K- and R-band observations
  86. GRB 060807: Refined analysis of the Swift-BAT burst
  87. GRB060807: optical afterglow candidate
  88. GRB060806 = SGR1806-20
  89. GRB 060805B: RHESSI Spectral Fit
  90. GRB060807: optical upper limit in white light
  91. IPN triangulation of GRB060806 (long, exceptionally bright)
  92. GRB060807 - SDSS Pre-burst Observations
  93. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  94. GRB 060805B: Swift/UVOT Upper Limits
  95. GRB 060807, optical observation
  96. GRB 060807: Kanazawa R-band observation
  97. GRB 060807: optical limit
  98. GRB 060807: Swift detection of a burst
  99. GRB 060801: Second Epoch WSRT Radio Observations
  100. IPN triangulation of GRB060805B

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