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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"

19362 results found.

  1. GRB 050922C: optical obserations
  2. GRB 050922C: NOT optical observations
  3. GRB 050922A: Analysis of Swift/XRT TOO observation
  4. GRB 050922C: Swift detection of a bright burst
  5. GRB 050922C: ROTSE-IIId Refined Analysis
  6. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  7. GRB 050922B: ROTSE-III Optical Limits
  8. GRB 050922B,optical observation
  9. GRB050922B: Swift-BAT detection of a weak long burst
  10. GRB050918: Possible Swift/XRT detected afterglow
  11. GRB050820B: analysis of the XMM-Newton observation
  12. GRB050916: Swift/UVOT Upper Limits
  13. GRB 050916: Swift-BAT refined analysis
  14. Swift-BAT trigger 155764 is not a GRB
  15. Swift-BAT trigger 155764 is probably not a GRB
  16. Swift trigger 155764: bad XRT centroid
  17. Swift-BAT trigger 155535 is definitely not a GRB
  18. GRB050916 : Swift-XRT refined analysis
  19. GRB 050916: XRT position
  20. GRB 050915B: Swift-BAT refined analysis
  21. GRB 050915B: Swift/UVOT Upper Limits
  22. GRB050916: Swift-BAT detection of a long weak burst
  23. GRB 050915B: XRT position
  24. GRB050915B: Swift-BAT detection of a long bright burst
  25. GRB050915: Swift/UVOT upper limits
  26. GRB 050915: KAIT optical limit
  27. GRB 050915: IR Observations
  28. GRB 050915: Swift XRT refined analysis
  29. GRB 050915: Swift-BAT refined analysis
  30. GRB050915, optical observations
  31. GRB050915: XRT position
  32. GRB 050915: ROTSE-III optical limits
  33. GRB 050915: Swift detection of a GRB
  34. GRB050911: Upper limit on X-ray afterglow
  35. Swift-BAT trigger 155072 ground analysis
  36. Swift-BAT trigger 155072 is probably not a GRB
  37. GRB050914: XRT position probably due to cosmic ray
  38. Swift is in normal operation
  39. GRB050911: Swift UVOT followup observations
  40. GRB 050911, optical content of Swift/XRT error box
  41. GRB050911: Swift-XRT position
  42. GRB 050911, optical observations
  43. GRB 050911: Swift-BAT refined analysis
  44. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  45. GRB050911: Swift-BAT detection of a long burst
  46. GRB050908: detection of Swift/UVOT optical counterpart
  47. RBO GRB 050908 observations
  48. WIRO observations in I of GRB 050908
  49. GRB 050906: Possible X-ray Counterpart
  50. GRB050908: Swift/UVOT Early upper limits
  51. GRB050908 : Swift-XRT refined analysis
  52. GRB 050908: Swift-BAT refined analysis
  53. GRB 050908: Optical observations
  54. Gemini Spectroscopy of GRB 050908
  55. GRB 050908 : Swift XRT position
  56. GRB 050908: KAIT observations
  57. GRB 050908: P60 Confirmation of Optical Afterglow
  58. GRB 050908: Swift detection of a burst
  59. Swift trigger 154073 is not a GRB
  60. GRB050904: CrAO optical observations
  61. GRB 050904 BAT refined analysis of complete data set
  62. GRB 050906: MARGE Optical Limits
  63. GRB 050906: Swift-BAT refined analysis
  64. GRB 050906: Swift XRT upper limit
  65. GRB050906: P60 Observations
  66. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  67. GRB 050906: Bright galaxy in BAT error box
  68. GRB 050906: Swift/BAT Detection of a possible burst
  69. GRB 050904: Swift/UVOT observations
  70. GRB 050904: early Swift XRT analysis results
  71. GRB 050904: BAT refined analysis of partial data set
  72. GRB050904: P60 Observations
  73. GRB 050904: TAROT optical limits
  74. GRB050904: Swift-BAT detection of a probable burst
  75. Swift-BAT triggers 153461-153465 are not GRBs
  76. Retraction of Swift-BAT trigger #153355
  77. GRB 050824: MDM Observations
  78. GRB 050827: Swift XRT preliminary analysis results
  79. Swift Trigger #152652 is not a GRB
  80. GRB050827: Swift/UVOT upper limits
  81. GRB 050827: Optical Limit
  82. GRB 050827: XRT possible afterglow detection
  83. GRB050827: RTT150 optical observations
  84. GRB 050827: Swift-BAT refined analysis
  85. GRB050827: Swift-BAT detection of a burst
  86. GRB 050826: Optical Candidate
  87. GRB050824, HETE-2 Observation
  88. GRB 050826: Swift XRT preliminary analysis results
  89. GRB 050826: BAT refined analysis
  90. GRB050826: Swift/UVOT early upper limits
  91. GRB050824: First 2 hours of power low optical decay?
  92. GRB 050826: Swift XRT position
  93. GRB050826: Swift-BAT detection of a long burst
  94. GRB050824: MASTER final analysis of the OT observations
  95. Possible GRB050825:MASTER optical observations
  96. Swift-BAT trigger 152038 is definitely not a GRB
  97. GRB050824: CORRECTION to UVOT observing times
  98. Swift-BAT trigger 152038 is probably not a GRB
  99. GRB050824: Swift/UVOT detection of fading afterglow
  100. GRB050824: decay of the XRT light curve and updated X-ray spectrum

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