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

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