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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 081215A: Andromeda inside Fermi error box: MASTER observations
  2. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  3. Possible GRB 081211B: Swift/UVOT Upper Limits
  4. GRB 081213: Fermi GBM detection
  5. GRB 081210: optical observations
  6. Possible GRB 081211B - Swift-XRT analysis
  7. GRB 081207: Fermi GBM detection
  8. GRB 081209: Fermi GBM detection
  9. Fermi Gamma-ray Burst Monitor trigger 250533995 is not a GRB
  10. GRB 081007: Detection of a Supernova
  11. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  12. GRB 081210: Xinglong TNT R band Upper Limits
  13. GRB 081210, SMARTS optical/IR observations
  14. GRB 081211: Swift-BAT refined analysis
  15. GRB 081211: Swift XRT refined analysis
  16. GRB 081211: Swift/UVOT detection of an optical afterglow
  17. GRB 081211: Enhanced Swift-XRT position
  18. GRB 081210: Swift/UVOT refined analysis
  19. GRB 081211: Swift detection of a burst
  20. GRB 081210: Swift-XRT refined analysis
  21. GRB081203B: optical observations
  22. GRB 081210: Enhanced Swift-XRT position
  23. GRB 081210: Swift-BAT refined analysis
  24. GRB 081210: Swift detection of a burst with optical afterglow
  25. Konus-Wind observation of GRB 081209
  26. IPN triangulation of short hard GRB 081209
  27. GRB 081203A: optical observations
  28. GRB 081206C: Fermi GBM detection
  29. Radio observation of GRB 081121 with ATCA
  30. Radio observation of GRB 081118 with ATCA
  31. GRB 081206B: Fermi GBM detection
  32. GRB 081206: Fermi GBM detection
  33. GRB 081128: afterglow observations
  34. GRB 081203B: Suzaku WAM observation of the prompt emission
  35. GRB 081203B: Additional Gemini imaging
  36. Radio observation of GRB 081109 with ATCA
  37. Radio observation of GRB 081104 with ATCA
  38. Radio observation of GRB 081029 with ATCA
  39. Radio observation of GRB 081008 with ATCA
  40. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  41. GRB 081203B: Gemini observations
  42. GRB 081128: optical observation in CrAO
  43. GRB081203A: Optical observations at Ishigaki
  44. GRB 081128: Optical afterglow observations
  45. GRB 081204: GROND Observations
  46. GRB081203B: optical observations
  47. Radio detection of GRB 081203B with the VLA
  48. GRB 081204: Magellan observations
  49. GRB081203A: Radio upper limit at 15 GHz
  50. GRB 081204B: Fermi GBM detection
  51. GRB 081204: Swift/UVOT Upper Limits
  52. GRB 081204: Swift XRT afterglow confirmation
  53. GRB081203A: MITSuME optical observation
  54. GRB 081203A: Optical observations of Xinglong TNT telescope
  55. GRB 081203A: Skynet/GORT Detections
  56. GRB 081204: Swift XRT afterglow candidate
  57. GRB081203A: optical observation
  58. GRB 081204 : a long GRB localized by INTEGRAL
  59. VLA Radio upper limit on GRB 081203A
  60. Swift-XRT observations of GRB 081203B
  61. Konus-Wind observation of GRB 081203A
  62. Konus-Wind observation of GRB 081203B
  63. GRB081203A: Swift-XRT refined analysis
  64. GRB 081203B: optical observations
  65. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  66. Swift/UVOT detection of GRB081203B
  67. GRB 081203B: Swift-XRT candidate afterglow.
  68. GRB 081203A: optical observations
  69. Swift UVOT observations of GRB 081203A
  70. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  71. GRB081203A: Swift/UVOT grism redshift
  72. GRB 081203A: Burst detection from Swift-BAT slew data
  73. GRB 081203A: Swift-BAT refined analysis
  74. GRB 081203: Enhanced Swift-XRT position
  75. GRB 081130B: MASTER prompt optical observations
  76. GRB081203: optical observation
  77. GRB 081203: Swift detection of a burst with a bright optical counterpart
  78. GRB 081128: optical observation
  79. GRB 081130B: Fermi GBM detection
  80. GRB 081130: Fermi GBM detection
  81. Swift Trigger 335971: Swift/UVOT Observations
  82. GRB 081126: afterglow photometry
  83. GRB 081126: Fermi GBM detection
  84. Fermi Gamma-ray Burst Monitor trigger 249166723 reclassification
  85. VLA Radio upper limit on GRB 081126
  86. GRB 081129: Fermi GBM detection
  87. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  88. GRB 081128A: optical observations
  89. Swift Trigger 335971 is probably not a real source
  90. Trigger 335971: Swift possible detection of a burst
  91. GRB081128: Swift/UVOT Upper Limits
  92. SGR 1806-20: Fermi GBM detection.
  93. GRB 081122B: Fermi GBM Detection
  94. GRB 081128: Swift-XRT refined analysis
  95. GRB 081128: Liverpool Telescope afterglow confirmation
  96. GRB081128: optical observations
  97. GRB081128 : Lulin optical follow-ups
  98. GRB 081128: Swift-BAT refined analysis
  99. GRB 081128: Enhanced Swift-XRT position
  100. GRB 081128: Optical observation of xinglong TNT

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