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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"

27499 results found.

  1. GRB 081210: optical observations
  2. Possible GRB 081211B - Swift-XRT analysis
  3. GRB 081207: Fermi GBM detection
  4. GRB 081209: Fermi GBM detection
  5. GRB 081007: Detection of a Supernova
  6. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  7. GRB 081210: Xinglong TNT R band Upper Limits
  8. GRB 081210, SMARTS optical/IR observations
  9. GRB 081211: Swift XRT refined analysis
  10. GRB 081211: Swift/UVOT detection of an optical afterglow
  11. GRB 081211: Enhanced Swift-XRT position
  12. GRB 081210: Swift/UVOT refined analysis
  13. GRB 081211: Swift detection of a burst
  14. GRB 081210: Swift-XRT refined analysis
  15. GRB 081210: Enhanced Swift-XRT position
  16. GRB 081210: Swift detection of a burst with optical afterglow
  17. GRB 081203A: optical observations
  18. GRB 081206C: Fermi GBM detection
  19. Radio observation of GRB 081121 with ATCA
  20. Radio observation of GRB 081118 with ATCA
  21. GRB 081206B: Fermi GBM detection
  22. GRB 081206: Fermi GBM detection
  23. GRB 081128: afterglow observations
  24. GRB 081203B: Additional Gemini imaging
  25. Radio observation of GRB 081109 with ATCA
  26. Radio observation of GRB 081104 with ATCA
  27. Radio observation of GRB 081029 with ATCA
  28. Radio observation of GRB 081008 with ATCA
  29. GRB 081203B: Gemini observations
  30. GRB 081128: optical observation in CrAO
  31. GRB 081128: Optical afterglow observations
  32. GRB 081204: GROND Observations
  33. GRB081203B: optical observations
  34. Radio detection of GRB 081203B with the VLA
  35. GRB 081204: Magellan observations
  36. GRB081203A: Radio upper limit at 15 GHz
  37. GRB 081204B: Fermi GBM detection
  38. GRB 081204: Swift/UVOT Upper Limits
  39. GRB 081204: Swift XRT afterglow confirmation
  40. GRB081203A: MITSuME optical observation
  41. GRB 081203A: Optical observations of Xinglong TNT telescope
  42. GRB 081203A: Skynet/GORT Detections
  43. GRB 081204: Swift XRT afterglow candidate
  44. GRB081203A: optical observation
  45. VLA Radio upper limit on GRB 081203A
  46. Swift-XRT observations of GRB 081203B
  47. GRB081203A: Swift-XRT refined analysis
  48. GRB 081203B: optical observations
  49. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  50. Swift/UVOT detection of GRB081203B
  51. GRB 081203B: Swift-XRT candidate afterglow.
  52. GRB 081203A: optical observations
  53. Swift UVOT observations of GRB 081203A
  54. GRB 081203A: Burst detection from Swift-BAT slew data
  55. GRB 081203: Enhanced Swift-XRT position
  56. GRB081203: optical observation
  57. GRB 081203: Swift detection of a burst with a bright optical counterpart
  58. GRB 081128: optical observation
  59. GRB 081130B: Fermi GBM detection
  60. GRB 081130: Fermi GBM detection
  61. GRB 081126: afterglow photometry
  62. GRB 081126: Fermi GBM detection
  63. VLA Radio upper limit on GRB 081126
  64. GRB 081129: Fermi GBM detection
  65. GRB 081128A: optical observations
  66. Swift Trigger 335971 is probably not a real source
  67. Trigger 335971: Swift possible detection of a burst
  68. GRB081128: Swift/UVOT Upper Limits
  69. SGR 1806-20: Fermi GBM detection.
  70. GRB 081122B: Fermi GBM Detection
  71. GRB 081128: Swift-XRT refined analysis
  72. GRB 081128: Liverpool Telescope afterglow confirmation
  73. GRB081128: optical observations
  74. GRB081128 : Lulin optical follow-ups
  75. GRB 081128: Enhanced Swift-XRT position
  76. GRB 081128: Optical observation of xinglong TNT
  77. GRB 081128: Swift detection of a burst
  78. GRB081126: Afterglow photometry from Crni Vrh
  79. GRB 081126: GRT Optical Observation
  80. GRB 081127: Swift/UVOT Upper Limits
  81. GRB 081127: Swift-XRT refined analysis
  82. GRB 081127: Enhanced Swift-XRT position
  83. GRB 081126: Confirmation of the Optical Afterglow
  84. GRB 081126: Swift-XRT refined analysis
  85. GRB 081127: Swift detection of a burst
  86. GRB 081126: Swift/UVOT Observations
  87. GRB 081126: optical observations
  88. GRB 081126: Enhanced Swift-XRT position
  89. GRB 081126: TAROT Calern observatory optical observations
  90. GRB 081126: Swift detection of a burst
  91. GRB 081125: Fermi GBM detection
  92. GRB 081124: Fermi GBM detection
  93. GRB 081120: Fermi GBM detection
  94. GRB 081118: Fermi GBM detection.
  95. GRB 081122: Fermi GBM detection
  96. GRB 081121, SMARTS optical/IR afterglow observations
  97. GRB081121: Fermi GBM detection
  98. Fermi GBM detection of a weak source
  99. GRB081121: Refined Swift/UVOT observations
  100. GRB 081121: Swift-XRT refined analysis

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