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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 060901: SMARTS optical/IR observations
  2. GRB 060901: Swift/XRT Position
  3. GRB 060901: further INTEGRAL results
  4. GRB 060901: Watcher observations
  5. GRB 060901: a long GRB detected by INTEGRAL
  6. Two bright bursts from SGR 1806-20 detected with IBAS
  7. GRB 060605, observations using an Integral Field Unit
  8. GRB 060604: VLA Observation
  9. GRB 060814: Suzaku/WAM observation of the prompt emission
  10. GRB 060605: VLA Observation
  11. GRB 060707: VLA observation
  12. GRB 060825: VLA observations
  13. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  14. Swift-BAT trigger 226614 is not a GRB
  15. GRB060826 - SDSS Pre-Burst Observations
  16. GRB 060826(?): Swift detection of a possible burst
  17. GRB 060825: XRT Team Refined Analysis
  18. GRB 060825: Swift-BAT Refined Analysis
  19. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  20. GRB060825: Liverpool Telescope optical observations
  21. GRB 060825: TNG optical observations
  22. GRB 060825: TAROT optical observations
  23. GRB 060825: P60 Observations
  24. GRB060825: BOOTES-IR optical observations
  25. GRB 060825: Swift detection of a burst
  26. GRB060801: host galaxy redshift
  27. GRB060729: analysis of XMM-Newton observation
  28. GRB 060814: pseudo-z from spectral parameters of the prompt
  29. IBAS Alerts No 3429 and 3430: not GRBs
  30. Radio observations of GRB 060719
  31. GRB 060729, SMARTS optical/IR observations
  32. GRB060814: Break in the XRT light curve
  33. GRB060813: Break in the XRT light curve
  34. GRB 060813: A long, bright GRB detected with Suzaku WAM
  35. GRB 060814: Confirmation of IR afterglow
  36. Konus-Wind observation of GRB 060814
  37. GRB 060814: Refined analysis of the Swift-BAT burst
  38. GRB 060814: P60 Observations
  39. GRB 060814: P200 NIR Observations
  40. GRB 060814: source inside revised XRT error box
  41. GRB 060814: Possible IR counterpart
  42. GRB060805B: optical observations
  43. GRB060814: Swift/UVOT upper limits
  44. GRB 060813: pseudo-z from spectral parameters of the prompt
  45. GRB 060814: Swift XRT refined analysis
  46. GRB 060814: VLT optical limits
  47. GRB 060814 - SDSS Pre-Burst Observations
  48. GRB 060814: TAROT optical observations
  49. GRB 060814: Swift detection of a bright burst
  50. Konus-Wind observation of GRB 060813
  51. GRB060813: Swift/UVOT upper limits
  52. GRB 060813: Swift XRT refined analysis
  53. GRB 060813: Refined analysis of the Swift-BAT burst
  54. GRB 060813: Swift detection of a burst
  55. GRB051109B: Late-time Radio Observations
  56. Image of the dust-scattering halo around SGR 1806-20
  57. Second VLA limit on new radio point source in SGR 1806-20
  58. A dust-scattering halo detected around SGR 1806-20
  59. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  60. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  61. GRB060807: Possible Highly Significant X-ray Emission Lines
  62. GRB060714: optical observations
  63. IBAS Alert n. 3422: not a GRB
  64. GRB 060729: An update on the Swift XRT and UVOT observations
  65. GRB060717: optical observations
  66. GRB060807: Optical limiting magnitudes
  67. GRB 060805B: optical observation at Sierra Nevada
  68. GRB 060805B: XRT Team Analysis
  69. VLA Upper Limit on Outburst of SGR 1806-20
  70. GRB060806 is similar to previous activity of SGR1806-20
  71. GRB 060807: UVOT Upper limits
  72. GRB 060807: afterglow confirmation
  73. GRB 060807: XRT Team refined analysis
  74. GRB 060807: K- and R-band observations
  75. GRB 060807: Refined analysis of the Swift-BAT burst
  76. GRB060807: optical afterglow candidate
  77. GRB060806 = SGR1806-20
  78. GRB 060805B: RHESSI Spectral Fit
  79. GRB060807: optical upper limit in white light
  80. IPN triangulation of GRB060806 (long, exceptionally bright)
  81. GRB060807 - SDSS Pre-burst Observations
  82. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  83. GRB 060805B: Swift/UVOT Upper Limits
  84. GRB 060807, optical observation
  85. GRB 060807: Kanazawa R-band observation
  86. GRB 060807: optical limit
  87. GRB 060807: Swift detection of a burst
  88. GRB 060801: Second Epoch WSRT Radio Observations
  89. IPN triangulation of GRB060805B
  90. GRB060805 Liverpool Telescope observations
  91. GRB 060805: optical upper limit in R
  92. GRB 060805: XRT Team Refined Analysis
  93. GRB 060805: Swift-BAT Refined Analysis
  94. GRB 060805: Swift/UVOT Upper Limits
  95. GRB 060805: P60 Observations
  96. GRB 060805: KAIT observations
  97. GRB 060805 - SDSS Pre-Burst Observations
  98. GRB 060805: Swift detection of a burst
  99. GRB 060804: Swift UVOT observations
  100. GRB 060804: Swift-XRT Team Refined Analysis

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