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

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