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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 060906 (?): P60 Optical Afterglow Candidate
  2. GRB 060906: Swift detection of a probable burst
  3. GRB 060904A Milagro GeV/TeV Observations
  4. GRB060904b, optical observations
  5. GRB 060904b: SMARTS optical/IR afterglow observations
  6. GRB 060904B: RTT150 optical observations
  7. GRB060904A: Swift/UVOT optical observations
  8. GRB 060904A: Subaru NIR observation
  9. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  10. GRB 060904B: Swift-BAT refined analysis
  11. GRB060904b: Optical observations with Swift/UVOT
  12. Konus-Wind observation of GRB 060904A
  13. GRB 060904B: Swift-XRT refined analysis
  14. GRB 060904A: Refined analysis of the Swift-BAT burst
  15. GRB 060904A: Swift-XRT refined analysis
  16. GRB 060904A: Suzaku-XIS and -HXD observation plan
  17. GRB 060904B: VLT redshift
  18. GRB 060904A: P60 Observations
  19. GRB 060904B: Optical observations at Crni Vrh
  20. GRB060904B: Watcher observations
  21. GRB 060904B BOOTES-IR and 1.5m OSN observations
  22. GRB 060904B: TAROT optical counterpart observations
  23. GRB060904B - SDSS Pre-Burst Observations
  24. GRB 060904: TAROT optical observations
  25. GRB 060904B: Swift detection of a burst with optical counterpart
  26. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  27. GRB060904 - SDSS Pre-Burst Observations
  28. GRB 060904: Swift detection of a bright burst
  29. GRB060901: Optical observations
  30. 060901: Swift UVOT followup observations
  31. GRB 060901: pseudo-z from spectral parameters of the prompt
  32. Konus-Wind observation of GRB 060901
  33. GRB 060901: SMARTS optical/IR observations update
  34. GRB 060901: Swift/XRT Refined Analysis
  35. GRB 060901: SMARTS optical/IR observations
  36. GRB 060901: Swift/XRT Position
  37. GRB 060901: further INTEGRAL results
  38. GRB 060901: Watcher observations
  39. GRB 060901: a long GRB detected by INTEGRAL
  40. Two bright bursts from SGR 1806-20 detected with IBAS
  41. GRB 060605, observations using an Integral Field Unit
  42. GRB 060604: VLA Observation
  43. GRB 060814: Suzaku/WAM observation of the prompt emission
  44. GRB 060605: VLA Observation
  45. GRB 060707: VLA observation
  46. GRB 060825: VLA observations
  47. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  48. Swift-BAT trigger 226614 is not a GRB
  49. GRB060826 - SDSS Pre-Burst Observations
  50. GRB 060826(?): Swift detection of a possible burst
  51. GRB 060825: XRT Team Refined Analysis
  52. GRB 060825: Swift-BAT Refined Analysis
  53. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  54. GRB060825: Liverpool Telescope optical observations
  55. GRB 060825: TNG optical observations
  56. GRB 060825: TAROT optical observations
  57. GRB 060825: P60 Observations
  58. GRB060825: BOOTES-IR optical observations
  59. GRB 060825: Swift detection of a burst
  60. GRB060801: host galaxy redshift
  61. GRB060729: analysis of XMM-Newton observation
  62. GRB 060814: pseudo-z from spectral parameters of the prompt
  63. IBAS Alerts No 3429 and 3430: not GRBs
  64. Radio observations of GRB 060719
  65. GRB 060729, SMARTS optical/IR observations
  66. GRB060814: Break in the XRT light curve
  67. GRB060813: Break in the XRT light curve
  68. GRB 060813: A long, bright GRB detected with Suzaku WAM
  69. GRB 060814: Confirmation of IR afterglow
  70. Konus-Wind observation of GRB 060814
  71. GRB 060814: Refined analysis of the Swift-BAT burst
  72. GRB 060814: P60 Observations
  73. GRB 060814: P200 NIR Observations
  74. GRB 060814: source inside revised XRT error box
  75. GRB 060814: Possible IR counterpart
  76. GRB060805B: optical observations
  77. GRB060814: Swift/UVOT upper limits
  78. GRB 060813: pseudo-z from spectral parameters of the prompt
  79. GRB 060814: Swift XRT refined analysis
  80. GRB 060814: VLT optical limits
  81. GRB 060814 - SDSS Pre-Burst Observations
  82. GRB 060814: TAROT optical observations
  83. GRB 060814: Swift detection of a bright burst
  84. Konus-Wind observation of GRB 060813
  85. GRB060813: Swift/UVOT upper limits
  86. GRB 060813: Swift XRT refined analysis
  87. GRB 060813: Refined analysis of the Swift-BAT burst
  88. GRB 060813: Swift detection of a burst
  89. GRB051109B: Late-time Radio Observations
  90. Image of the dust-scattering halo around SGR 1806-20
  91. Second VLA limit on new radio point source in SGR 1806-20
  92. A dust-scattering halo detected around SGR 1806-20
  93. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  94. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  95. GRB060807: Possible Highly Significant X-ray Emission Lines
  96. GRB060714: optical observations
  97. IBAS Alert n. 3422: not a GRB
  98. GRB 060729: An update on the Swift XRT and UVOT observations
  99. GRB060717: optical observations
  100. GRB060807: Optical limiting magnitudes

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