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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"

18405 results found.

  1. GRB051008: Swift XRT refined analysis
  2. GRB051008 - Swift UVOT upper limits
  3. Konus-Wind observation of GRB 051008
  4. GRB051008: Final refined analysis of the Swift-BAT burst
  5. GRB 051008: R-band upper limit
  6. GRB051008: Refined analysis of the Swift-BAT burst
  7. GRB 051008: Swift XRT position
  8. GRB 051008: early Swift XRT analysis
  9. GRB 051008: Swift UVOT Candidate
  10. GRB051008: Swift-BAT detection of a bright burst
  11. GRB 051006: XRT refined analysis
  12. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  13. GRB 051006: optical observations at Sierra Nevada
  14. GRB051006: Refined analysis of the Swift-BAT burst
  15. GRB 051006: XRT position
  16. GRB051006: Swift detection of a burst
  17. Swift-BAT triggers 158261 and 158262 Retraction
  18. GRB051001: Swift UVOT Upper Limits
  19. GRB 050925: Second Epoch WSRT Radio Observations
  20. GRB 051001: Swift XRT refined analysis
  21. GRB 051001, optical observations at Mt. John
  22. GRB 051001: I-band limit
  23. GRB 051001: Swift-BAT refined analysis
  24. GRB 051001: Swift Detection of a Burst
  25. GRB 051001: ROTSE-III Optical Limits
  26. GRB050922B: optical limit
  27. GRB050925: Swift/XRT limits
  28. GRB/SGR 050925: IR Observations
  29. GRB050922C - Swift UVOT preliminary analysis
  30. GRB 050925: WSRT Radio Observations
  31. GRB050925: Swift UVOT upper limits
  32. Refined analysis of the Swift-BAT soft short burst
  33. GRB050925: Faulkes Telescope North R-band limit
  34. GRB050925: Swift-BAT detection of a short burst
  35. GRB 050922B: Correction to BAT refined analysis, longer burst
  36. GRB050922B: refined XRT analysis
  37. Konus-Wind observation of GRB 050922C
  38. GRB050922B: Swift UVOT early upper limits.
  39. GRB 050922B: optical limit
  40. GRB 050922C: Swift XRT refined analysis
  41. HETE Fregate observations of GRB 050922C
  42. GRB 050922C: Swift-BAT refined analysis
  43. GRB 050922B: Swift-BAT refined analysis
  44. GRB050922C: optical observations
  45. GRB 050922C: Absorption redshift from the Nordic Optical Telescope
  46. GRB 050922C: optical obserations
  47. GRB 050922C: NOT optical observations
  48. GRB 050922A: Analysis of Swift/XRT TOO observation
  49. GRB 050922C: Swift detection of a bright burst
  50. GRB 050922C: ROTSE-IIId Refined Analysis
  51. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  52. GRB 050922B: ROTSE-III Optical Limits
  53. GRB 050922B,optical observation
  54. GRB050922B: Swift-BAT detection of a weak long burst
  55. GRB050918: Possible Swift/XRT detected afterglow
  56. GRB050820B: analysis of the XMM-Newton observation
  57. GRB050916: Swift/UVOT Upper Limits
  58. GRB 050916: Swift-BAT refined analysis
  59. Swift-BAT trigger 155764 is not a GRB
  60. Swift-BAT trigger 155764 is probably not a GRB
  61. Swift trigger 155764: bad XRT centroid
  62. Swift-BAT trigger 155535 is definitely not a GRB
  63. GRB050916 : Swift-XRT refined analysis
  64. GRB 050916: XRT position
  65. GRB 050915B: Swift-BAT refined analysis
  66. GRB 050915B: Swift/UVOT Upper Limits
  67. GRB050916: Swift-BAT detection of a long weak burst
  68. GRB 050915B: XRT position
  69. GRB050915B: Swift-BAT detection of a long bright burst
  70. GRB050915: Swift/UVOT upper limits
  71. GRB 050915: KAIT optical limit
  72. GRB 050915: IR Observations
  73. GRB 050915: Swift XRT refined analysis
  74. GRB 050915: Swift-BAT refined analysis
  75. GRB050915, optical observations
  76. GRB050915: XRT position
  77. GRB 050915: ROTSE-III optical limits
  78. GRB 050915: Swift detection of a GRB
  79. GRB050911: Upper limit on X-ray afterglow
  80. Swift-BAT trigger 155072 ground analysis
  81. Swift-BAT trigger 155072 is probably not a GRB
  82. GRB050914: XRT position probably due to cosmic ray
  83. Swift is in normal operation
  84. GRB050911: Swift UVOT followup observations
  85. GRB 050911, optical content of Swift/XRT error box
  86. GRB050911: Swift-XRT position
  87. GRB 050911, optical observations
  88. GRB 050911: Swift-BAT refined analysis
  89. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  90. GRB050911: Swift-BAT detection of a long burst
  91. GRB050908: detection of Swift/UVOT optical counterpart
  92. RBO GRB 050908 observations
  93. WIRO observations in I of GRB 050908
  94. GRB 050906: Possible X-ray Counterpart
  95. GRB050908: Swift/UVOT Early upper limits
  96. GRB050908 : Swift-XRT refined analysis
  97. GRB 050908: Swift-BAT refined analysis
  98. GRB 050908: Optical observations
  99. Gemini Spectroscopy of GRB 050908
  100. GRB 050908 : Swift XRT position

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