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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 081211: Swift/UVOT detection of an optical afterglow
  2. GRB 081211: Enhanced Swift-XRT position
  3. GRB 081210: Swift/UVOT refined analysis
  4. GRB 081211: Swift detection of a burst
  5. GRB 081210: Swift-XRT refined analysis
  6. GRB081203B: optical observations
  7. GRB 081210: Enhanced Swift-XRT position
  8. GRB 081210: Swift-BAT refined analysis
  9. GRB 081210: Swift detection of a burst with optical afterglow
  10. Konus-Wind observation of GRB 081209
  11. IPN triangulation of short hard GRB 081209
  12. GRB 081203A: optical observations
  13. GRB 081206C: Fermi GBM detection
  14. Radio observation of GRB 081121 with ATCA
  15. Radio observation of GRB 081118 with ATCA
  16. GRB 081206B: Fermi GBM detection
  17. GRB 081206: Fermi GBM detection
  18. GRB 081128: afterglow observations
  19. GRB 081203B: Suzaku WAM observation of the prompt emission
  20. GRB 081203B: Additional Gemini imaging
  21. Radio observation of GRB 081109 with ATCA
  22. Radio observation of GRB 081104 with ATCA
  23. Radio observation of GRB 081029 with ATCA
  24. Radio observation of GRB 081008 with ATCA
  25. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  26. GRB 081203B: Gemini observations
  27. GRB 081128: optical observation in CrAO
  28. GRB081203A: Optical observations at Ishigaki
  29. GRB 081128: Optical afterglow observations
  30. GRB 081204: GROND Observations
  31. GRB081203B: optical observations
  32. Radio detection of GRB 081203B with the VLA
  33. GRB 081204: Magellan observations
  34. GRB081203A: Radio upper limit at 15 GHz
  35. GRB 081204B: Fermi GBM detection
  36. GRB 081204: Swift/UVOT Upper Limits
  37. GRB 081204: Swift XRT afterglow confirmation
  38. GRB081203A: MITSuME optical observation
  39. GRB 081203A: Optical observations of Xinglong TNT telescope
  40. GRB 081203A: Skynet/GORT Detections
  41. GRB 081204: Swift XRT afterglow candidate
  42. GRB081203A: optical observation
  43. GRB 081204 : a long GRB localized by INTEGRAL
  44. VLA Radio upper limit on GRB 081203A
  45. Swift-XRT observations of GRB 081203B
  46. Konus-Wind observation of GRB 081203A
  47. Konus-Wind observation of GRB 081203B
  48. GRB081203A: Swift-XRT refined analysis
  49. GRB 081203B: optical observations
  50. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  51. Swift/UVOT detection of GRB081203B
  52. GRB 081203B: Swift-XRT candidate afterglow.
  53. GRB 081203A: optical observations
  54. Swift UVOT observations of GRB 081203A
  55. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  56. GRB081203A: Swift/UVOT grism redshift
  57. GRB 081203A: Burst detection from Swift-BAT slew data
  58. GRB 081203A: Swift-BAT refined analysis
  59. GRB 081203: Enhanced Swift-XRT position
  60. GRB 081130B: MASTER prompt optical observations
  61. GRB081203: optical observation
  62. GRB 081203: Swift detection of a burst with a bright optical counterpart
  63. GRB 081128: optical observation
  64. GRB 081130B: Fermi GBM detection
  65. GRB 081130: Fermi GBM detection
  66. Swift Trigger 335971: Swift/UVOT Observations
  67. GRB 081126: afterglow photometry
  68. GRB 081126: Fermi GBM detection
  69. Fermi Gamma-ray Burst Monitor trigger 249166723 reclassification
  70. VLA Radio upper limit on GRB 081126
  71. GRB 081129: Fermi GBM detection
  72. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  73. GRB 081128A: optical observations
  74. Swift Trigger 335971 is probably not a real source
  75. Trigger 335971: Swift possible detection of a burst
  76. GRB081128: Swift/UVOT Upper Limits
  77. SGR 1806-20: Fermi GBM detection.
  78. GRB 081122B: Fermi GBM Detection
  79. GRB 081128: Swift-XRT refined analysis
  80. GRB 081128: Liverpool Telescope afterglow confirmation
  81. GRB081128: optical observations
  82. GRB081128 : Lulin optical follow-ups
  83. GRB 081128: Swift-BAT refined analysis
  84. GRB 081128: Enhanced Swift-XRT position
  85. GRB 081128: Optical observation of xinglong TNT
  86. GRB 081128: Swift detection of a burst
  87. GRB 081126: Swift observations continuing
  88. GRB081126: Afterglow photometry from Crni Vrh
  89. GRB 081126: GRT Optical Observation
  90. GRB 081127: Swift/UVOT Upper Limits
  91. GRB 081127: Swift-XRT refined analysis
  92. GRB 081127: Enhanced Swift-XRT position
  93. GRB 081126: Confirmation of the Optical Afterglow
  94. GRB 081127: Swift-BAT refined analysis
  95. Konus-Wind observation of GRB 081126
  96. GRB 081126: Swift-XRT refined analysis
  97. GRB 081127: Swift detection of a burst
  98. GRB 081126: Swift/UVOT Observations
  99. GRB 081126: optical observations
  100. GRB 081126: Swift-BAT refined analysis

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