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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"

19589 results found.

  1. Swift-BAT triggers 158261 and 158262 Retraction
  2. GRB051001: Swift UVOT Upper Limits
  3. GRB 050925: Second Epoch WSRT Radio Observations
  4. GRB 051001: Swift XRT refined analysis
  5. GRB 051001, optical observations at Mt. John
  6. GRB 051001: I-band limit
  7. GRB 051001: Swift-BAT refined analysis
  8. GRB 051001: Swift Detection of a Burst
  9. GRB 051001: ROTSE-III Optical Limits
  10. GRB050922B: optical limit
  11. GRB050925: Swift/XRT limits
  12. GRB/SGR 050925: IR Observations
  13. GRB050922C - Swift UVOT preliminary analysis
  14. GRB 050925: WSRT Radio Observations
  15. GRB050925: Swift UVOT upper limits
  16. Refined analysis of the Swift-BAT soft short burst
  17. GRB050925: Faulkes Telescope North R-band limit
  18. GRB050925: Swift-BAT detection of a short burst
  19. GRB 050922B: Correction to BAT refined analysis, longer burst
  20. GRB050922B: refined XRT analysis
  21. Konus-Wind observation of GRB 050922C
  22. GRB050922B: Swift UVOT early upper limits.
  23. GRB 050922B: optical limit
  24. GRB 050922C: Swift XRT refined analysis
  25. HETE Fregate observations of GRB 050922C
  26. GRB 050922C: Swift-BAT refined analysis
  27. GRB 050922B: Swift-BAT refined analysis
  28. GRB050922C: optical observations
  29. GRB 050922C: Absorption redshift from the Nordic Optical Telescope
  30. GRB 050922C: optical obserations
  31. GRB 050922C: NOT optical observations
  32. GRB 050922A: Analysis of Swift/XRT TOO observation
  33. GRB 050922C: Swift detection of a bright burst
  34. GRB 050922C: ROTSE-IIId Refined Analysis
  35. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  36. GRB 050922B: ROTSE-III Optical Limits
  37. GRB 050922B,optical observation
  38. GRB050922B: Swift-BAT detection of a weak long burst
  39. GRB050918: Possible Swift/XRT detected afterglow
  40. GRB050820B: analysis of the XMM-Newton observation
  41. GRB050916: Swift/UVOT Upper Limits
  42. GRB 050916: Swift-BAT refined analysis
  43. Swift-BAT trigger 155764 is not a GRB
  44. Swift-BAT trigger 155764 is probably not a GRB
  45. Swift trigger 155764: bad XRT centroid
  46. Swift-BAT trigger 155535 is definitely not a GRB
  47. GRB050916 : Swift-XRT refined analysis
  48. GRB 050916: XRT position
  49. GRB 050915B: Swift-BAT refined analysis
  50. GRB 050915B: Swift/UVOT Upper Limits
  51. GRB050916: Swift-BAT detection of a long weak burst
  52. GRB 050915B: XRT position
  53. GRB050915B: Swift-BAT detection of a long bright burst
  54. GRB050915: Swift/UVOT upper limits
  55. GRB 050915: KAIT optical limit
  56. GRB 050915: IR Observations
  57. GRB 050915: Swift XRT refined analysis
  58. GRB 050915: Swift-BAT refined analysis
  59. GRB050915, optical observations
  60. GRB050915: XRT position
  61. GRB 050915: ROTSE-III optical limits
  62. GRB 050915: Swift detection of a GRB
  63. GRB050911: Upper limit on X-ray afterglow
  64. Swift-BAT trigger 155072 ground analysis
  65. Swift-BAT trigger 155072 is probably not a GRB
  66. GRB050914: XRT position probably due to cosmic ray
  67. Swift is in normal operation
  68. GRB050911: Swift UVOT followup observations
  69. GRB 050911, optical content of Swift/XRT error box
  70. GRB050911: Swift-XRT position
  71. GRB 050911, optical observations
  72. GRB 050911: Swift-BAT refined analysis
  73. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  74. GRB050911: Swift-BAT detection of a long burst
  75. GRB050908: detection of Swift/UVOT optical counterpart
  76. RBO GRB 050908 observations
  77. WIRO observations in I of GRB 050908
  78. GRB 050906: Possible X-ray Counterpart
  79. GRB050908: Swift/UVOT Early upper limits
  80. GRB050908 : Swift-XRT refined analysis
  81. GRB 050908: Swift-BAT refined analysis
  82. GRB 050908: Optical observations
  83. Gemini Spectroscopy of GRB 050908
  84. GRB 050908 : Swift XRT position
  85. GRB 050908: KAIT observations
  86. GRB 050908: P60 Confirmation of Optical Afterglow
  87. GRB 050908: Swift detection of a burst
  88. Swift trigger 154073 is not a GRB
  89. GRB050904: CrAO optical observations
  90. GRB 050904 BAT refined analysis of complete data set
  91. GRB 050906: MARGE Optical Limits
  92. GRB 050906: Swift-BAT refined analysis
  93. GRB 050906: Swift XRT upper limit
  94. GRB050906: P60 Observations
  95. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  96. GRB 050906: Bright galaxy in BAT error box
  97. GRB 050906: Swift/BAT Detection of a possible burst
  98. GRB 050904: Swift/UVOT observations
  99. GRB 050904: early Swift XRT analysis results
  100. GRB 050904: BAT refined analysis of partial data set

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