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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"

17853 results found.

  1. GRB 081222, Swift-BAT refined analysis
  2. GRB081222 optical limit by "Pi of the Sky"
  3. GRB 081222: Swift XRT refined analysis
  4. GRB081221: Fermi GBM observation
  5. IPN triangulation of bright GRB 081215A
  6. GRB 081221: Swift-XRT Refined Analysis
  7. GRB 081222: Faulkes Telescope South observations
  8. GRB 081221: Gemini-N nIR imaging
  9. GRB081222, optical observation
  10. GRB081203A: BTA observation
  11. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  12. GRB081222: REM candidate afterglow
  13. GRB 081222: Swift detection of a burst with a bright optical afterglow
  14. GRB 081221: Enhanced Swift-XRT position
  15. GRB 081221: further NOT observations
  16. GRB 081221: NOT observations
  17. GRB 081221: Swift detection of a burst
  18. GRB 081118: Zadko observations
  19. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  20. GRB 0811215A: MASTER prompt optical observations
  21. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  22. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  23. Possible GRB 081211B: Swift/UVOT Upper Limits
  24. Possible GRB 081211B - Swift-XRT analysis
  25. GRB 081209: Fermi GBM detection
  26. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  27. GRB 081210, SMARTS optical/IR observations
  28. GRB 081211: Enhanced Swift-XRT position
  29. GRB 081211: Swift detection of a burst
  30. GRB081203B: optical observations
  31. GRB 081210: Enhanced Swift-XRT position
  32. GRB 081210: Swift detection of a burst with optical afterglow
  33. IPN triangulation of short hard GRB 081209
  34. GRB 081203A: optical observations
  35. GRB 081128: afterglow observations
  36. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  37. GRB081203A: Optical observations at Ishigaki
  38. GRB 081204: GROND Observations
  39. Radio detection of GRB 081203B with the VLA
  40. GRB081203A: Radio upper limit at 15 GHz
  41. GRB 081204: Swift/UVOT Upper Limits
  42. GRB081203A: MITSuME optical observation
  43. GRB081203A: optical observation
  44. VLA Radio upper limit on GRB 081203A
  45. GRB 081203B: optical observations
  46. Swift/UVOT detection of GRB081203B
  47. GRB 081203B: Swift-XRT candidate afterglow.
  48. GRB 081203A: optical observations
  49. GRB 081203: Enhanced Swift-XRT position
  50. GRB 081130B: MASTER prompt optical observations
  51. GRB081203: optical observation
  52. GRB 081203: Swift detection of a burst with a bright optical counterpart
  53. Swift Trigger 335971: Swift/UVOT Observations
  54. GRB 081126: afterglow photometry
  55. VLA Radio upper limit on GRB 081126
  56. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  57. GRB 081128A: optical observations
  58. Trigger 335971: Swift possible detection of a burst
  59. GRB081128: Swift/UVOT Upper Limits
  60. GRB 081128: Liverpool Telescope afterglow confirmation
  61. GRB081128: optical observations
  62. GRB 081128: Enhanced Swift-XRT position
  63. GRB 081128: Optical observation of xinglong TNT
  64. GRB 081128: Swift detection of a burst
  65. GRB 081126: GRT Optical Observation
  66. GRB 081127: Swift/UVOT Upper Limits
  67. GRB 081127: Enhanced Swift-XRT position
  68. GRB 081127: Swift detection of a burst
  69. GRB 081126: Swift/UVOT Observations
  70. GRB 081126: optical observations
  71. GRB 081126: Enhanced Swift-XRT position
  72. GRB 081126: TAROT Calern observatory optical observations
  73. GRB 081126: Swift detection of a burst
  74. GRB 081121, SMARTS optical/IR afterglow observations
  75. GRB081121: Refined Swift/UVOT observations
  76. GRB 081121: Swift-XRT refined analysis
  77. GRB 081121: Enhanced Swift-XRT position
  78. GRB 081121: GROND observations
  79. GRB081121: Swift/UVOT observations
  80. GRB081118 : optical upper limit
  81. VLA Radio upper limit on GRB 081118
  82. GRB 081118: Swift-XRT refined analysis
  83. GRB 081118: GROND detection of afterglow
  84. GRB 081118: optical afterglow candidate
  85. GRB 081118: Swift UVOT Upper Limits
  86. GRB 081118: Enhanced Swift-XRT position
  87. GRB 081118: Swift detection of a burst
  88. GRB 081109A: confirmation of possible detection host galaxy
  89. Further Swift-XRT observations of the probable GRB 081105.
  90. GRB 081102: RTT150 Optical observations
  91. GRB 081110: Fermi GBM detection
  92. GRB 081109: TAROT La Silla observatory optical observations
  93. GRB 081102: MASTER refind and final results
  94. GRB 081109: GROND redshift limit and host extinction
  95. GRB 081025: Swift-XRT further analysis
  96. GRB 081024B: Swift-XRT late-time observations
  97. GRB 081109B: Swift/UVOT refined analysis
  98. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  99. GRB 081109A: Swift-XRT refined analysis
  100. GRB 081109: Swift/UVOT upper limits

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