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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"

21786 results found.

  1. GRB 121211A: Swift-BAT refined analysis
  2. GRB 121212A: Enhanced Swift-XRT position
  3. GRB 121212A: Swift detection of a burst
  4. GRB 121211A: Swift/UVOT Detection
  5. GRB 121211A: MITSuME Okayama Optical Observation
  6. GRB 121211A: Enhanced Swift-XRT position
  7. GRB 121211A: Swift detection of a burst with an optical counterpart
  8. GRB 121209A: Swift-BAT refined analysis
  9. GRB 121209A: Enhanced Swift-XRT position
  10. GRB 121209A: GROND optical afterglow candidate
  11. GRB 121209A: Gemini-South imaging
  12. GRB 121209A: PAIRITEL NIR Observations
  13. GRB 121209A: Swift detection of a burst
  14. GRB 121127A: Suzaku WAM observation of the prompt emission
  15. GRB 121128A: Optical Observations
  16. GRB 121122A: Suzaku WAM observation of the prompt emission
  17. GRB 121202A: Swift/UVOT Upper Limits
  18. GRB 121202A: Enhanced Swift-XRT position
  19. GRB 121202A: Swift-XRT observations
  20. GRB121202A: Swift/UVOT Observations
  21. GRB 121202A: TAROT Calern observatory optical observations
  22. GRB 121201A: GROND afterglow observations and photometric redshift
  23. GRB 121201A: Swift/UVOT Detection
  24. GRB 121201A: Enhanced Swift-XRT position
  25. GRB 121201A: a GRB with an optical counterpart
  26. GRB 121128A: optical observation in Mondy observatory
  27. Konus-Wind observation of GRB 121127A
  28. GRB 121125A: optical upper limit
  29. GRB 121128A: optical observation in Mondy observatory
  30. GRB 121128A: Swift/UVOT Detection
  31. GRB 121128A: Enhanced Swift-XRT position
  32. GRB 121128A: RAPTOR Detection During Gamma-Ray Emitting Interval
  33. GRB 121128A: Swift detection of a burst with an optical counterpart
  34. GRB 121123A: Suzaku WAM observation of the prompt emission
  35. Konus-Wind observation of GRB 121122A
  36. GRB 121117A: Terskol obseravtions
  37. GRB 121123A: Swift/UVOT Observations
  38. GRB 121125A: Swift/UVOT Detection
  39. IPN Triangulation of GRB 121122A (long/intense)
  40. GRB 121118B: Suzaku WAM observation of the prompt emission
  41. GRB 121125A: Enhanced Swift-XRT position
  42. GRB 121125A: LOAO Observation
  43. GRB 121125A: MASTER-NET optical observations
  44. GRB 121125A: Swift detection of a burst with optical counterpart
  45. GRB 121123A: GROND observations
  46. GRB 121123A: Enhanced Swift-XRT position
  47. GRB 121123A: Swift-BAT refined analysis
  48. GRB 121123A: optical observations
  49. GRB 121123A: NOT optical observations
  50. GRB 121123A: MASTER-NET optical limit
  51. GRB 121123A: GMG optical observation
  52. GRB 121123A: Swift detection of a burst with optical counterpart
  53. GRB 121108A: optical upper limit
  54. GRB 121117A: Optical observations
  55. Konus-Wind observation of GRB 121118B
  56. GRB 121117A: optical upper limit
  57. IPN Triangulation of GRB 121118B (long/intense)
  58. GRB 121117A: GROND confirmation of the UVOT afterglow candidate
  59. GRB 121117A: Swift/UVOT Observations
  60. GRB 121117A: Swift-XRT refined Analysis
  61. GRB 121117A: MASTER prompt optical limit
  62. GRB 121117A, Swift-BAT refined analysis
  63. GRB 121117A: ROTSE-III Optical Limits
  64. GRB 121117A: BOOTES-3 early optical upper limit
  65. GRB 121117A: Swift detection of a burst
  66. GRB 121108A: Swift/UVOT Upper Limits
  67. GRB 121108A: Enhanced Swift-XRT position
  68. GRB 121108A : Lulin/TRIPOL2 Optical Limits
  69. GRB 121108A: MITSuME Ishigakijima upper limits
  70. GRB 121108A: Weihai observatory optical observations
  71. GRB 121108A: MASTER early prompt optical limit
  72. GRB 121108A: TAROT Calern observatory optical observations
  73. GRB 121108A: Swift detection of a burst
  74. GRB 121028A: Swift/UVOT Upper Limits
  75. GRB 121031A, Early peak observed with Swift-BAT
  76. GRB 121102A: Swift/UVOT Upper Limits
  77. GRB 121031A: Swift/UVOT Upper Limits
  78. GRB 121102A: Enhanced Swift-XRT position
  79. GRB 121031A: Enhanced Swift-XRT position
  80. GRB 121102A: Swift-XRT refined Analysis
  81. GRB 121029A Suzaku WAM observation of the prompt emission
  82. GRB 121102A: Swift detection of a burst
  83. GRB 121031A: Swift detection of a burst
  84. GRB 121027A: Swift/UVOT Possible Detection
  85. GRB 121024A: SMARTS optical/IR afterglow observations
  86. GRB 121027A: GROND Confirmation of Rebrightening
  87. GRB 121028A: RAPTOR Limits During Gamma-Ray Emitting Interval
  88. GRB 121027A: MASTER early prompt optical limit
  89. GRB 121028A: Enhanced Swift-XRT position
  90. GRB 121027A: Enhanced Swift-XRT position
  91. GRB 121028A: MITSuME Okayama Optical upper limits
  92. GRB 121028A: Swift detection of a burst
  93. GRB 121011A: optical observations
  94. GRB 121027A: nIR afterglow candidate with AAT
  95. GRB 121027A: Swift detection of a burst
  96. GRB 121024A: optical observations
  97. GRB 121024A: Swift/UVOT Observations
  98. GRB 121024A: GMG optical observation
  99. GRB 121024A: MITSuME Ishigakijima upper limits
  100. GRB 121024A: MITSuME Okayama Optical upper limits

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