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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: a long GRB detected by INTEGRAL
  2. Two bright bursts from SGR 1806-20 detected with IBAS
  3. GRB 060605, observations using an Integral Field Unit
  4. GRB 060604: VLA Observation
  5. GRB 060814: Suzaku/WAM observation of the prompt emission
  6. GRB 060605: VLA Observation
  7. GRB 060707: VLA observation
  8. GRB 060825: VLA observations
  9. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  10. Swift-BAT trigger 226614 is not a GRB
  11. GRB060826 - SDSS Pre-Burst Observations
  12. GRB 060826(?): Swift detection of a possible burst
  13. GRB 060825: XRT Team Refined Analysis
  14. GRB 060825: Swift-BAT Refined Analysis
  15. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  16. GRB060825: Liverpool Telescope optical observations
  17. GRB 060825: TNG optical observations
  18. GRB 060825: TAROT optical observations
  19. GRB 060825: P60 Observations
  20. GRB060825: BOOTES-IR optical observations
  21. GRB 060825: Swift detection of a burst
  22. GRB060801: host galaxy redshift
  23. GRB060729: analysis of XMM-Newton observation
  24. GRB 060814: pseudo-z from spectral parameters of the prompt
  25. IBAS Alerts No 3429 and 3430: not GRBs
  26. Radio observations of GRB 060719
  27. GRB 060729, SMARTS optical/IR observations
  28. GRB060814: Break in the XRT light curve
  29. GRB060813: Break in the XRT light curve
  30. GRB 060813: A long, bright GRB detected with Suzaku WAM
  31. GRB 060814: Confirmation of IR afterglow
  32. Konus-Wind observation of GRB 060814
  33. GRB 060814: Refined analysis of the Swift-BAT burst
  34. GRB 060814: P60 Observations
  35. GRB 060814: P200 NIR Observations
  36. GRB 060814: source inside revised XRT error box
  37. GRB 060814: Possible IR counterpart
  38. GRB060805B: optical observations
  39. GRB060814: Swift/UVOT upper limits
  40. GRB 060813: pseudo-z from spectral parameters of the prompt
  41. GRB 060814: Swift XRT refined analysis
  42. GRB 060814: VLT optical limits
  43. GRB 060814 - SDSS Pre-Burst Observations
  44. GRB 060814: TAROT optical observations
  45. GRB 060814: Swift detection of a bright burst
  46. Konus-Wind observation of GRB 060813
  47. GRB060813: Swift/UVOT upper limits
  48. GRB 060813: Swift XRT refined analysis
  49. GRB 060813: Refined analysis of the Swift-BAT burst
  50. GRB 060813: Swift detection of a burst
  51. GRB051109B: Late-time Radio Observations
  52. Image of the dust-scattering halo around SGR 1806-20
  53. Second VLA limit on new radio point source in SGR 1806-20
  54. A dust-scattering halo detected around SGR 1806-20
  55. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  56. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  57. GRB060807: Possible Highly Significant X-ray Emission Lines
  58. GRB060714: optical observations
  59. IBAS Alert n. 3422: not a GRB
  60. GRB 060729: An update on the Swift XRT and UVOT observations
  61. GRB060717: optical observations
  62. GRB060807: Optical limiting magnitudes
  63. GRB 060805B: optical observation at Sierra Nevada
  64. GRB 060805B: XRT Team Analysis
  65. VLA Upper Limit on Outburst of SGR 1806-20
  66. GRB060806 is similar to previous activity of SGR1806-20
  67. GRB 060807: UVOT Upper limits
  68. GRB 060807: afterglow confirmation
  69. GRB 060807: XRT Team refined analysis
  70. GRB 060807: K- and R-band observations
  71. GRB 060807: Refined analysis of the Swift-BAT burst
  72. GRB060807: optical afterglow candidate
  73. GRB060806 = SGR1806-20
  74. GRB 060805B: RHESSI Spectral Fit
  75. GRB060807: optical upper limit in white light
  76. IPN triangulation of GRB060806 (long, exceptionally bright)
  77. GRB060807 - SDSS Pre-burst Observations
  78. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  79. GRB 060805B: Swift/UVOT Upper Limits
  80. GRB 060807, optical observation
  81. GRB 060807: Kanazawa R-band observation
  82. GRB 060807: optical limit
  83. GRB 060807: Swift detection of a burst
  84. GRB 060801: Second Epoch WSRT Radio Observations
  85. IPN triangulation of GRB060805B
  86. GRB060805 Liverpool Telescope observations
  87. GRB 060805: optical upper limit in R
  88. GRB 060805: XRT Team Refined Analysis
  89. GRB 060805: Swift-BAT Refined Analysis
  90. GRB 060805: Swift/UVOT Upper Limits
  91. GRB 060805: P60 Observations
  92. GRB 060805: KAIT observations
  93. GRB 060805 - SDSS Pre-Burst Observations
  94. GRB 060805: Swift detection of a burst
  95. GRB 060804: Swift UVOT observations
  96. GRB 060804: Swift-XRT Team Refined Analysis
  97. GRB 060804: Refined analysis of the Swift-BAT burst
  98. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  99. GRB 060728: Upper limits of the X-ray emission
  100. GRB 060801: no variability of optical sources

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