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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"

19356 results found.

  1. GRB 050922C: ROTSE-IIId Refined Analysis
  2. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  3. GRB 050922B: ROTSE-III Optical Limits
  4. GRB 050922B,optical observation
  5. GRB050922B: Swift-BAT detection of a weak long burst
  6. GRB050918: Possible Swift/XRT detected afterglow
  7. GRB050820B: analysis of the XMM-Newton observation
  8. GRB050916: Swift/UVOT Upper Limits
  9. GRB 050916: Swift-BAT refined analysis
  10. Swift-BAT trigger 155764 is not a GRB
  11. Swift-BAT trigger 155764 is probably not a GRB
  12. Swift trigger 155764: bad XRT centroid
  13. Swift-BAT trigger 155535 is definitely not a GRB
  14. GRB050916 : Swift-XRT refined analysis
  15. GRB 050916: XRT position
  16. GRB 050915B: Swift-BAT refined analysis
  17. GRB 050915B: Swift/UVOT Upper Limits
  18. GRB050916: Swift-BAT detection of a long weak burst
  19. GRB 050915B: XRT position
  20. GRB050915B: Swift-BAT detection of a long bright burst
  21. GRB050915: Swift/UVOT upper limits
  22. GRB 050915: KAIT optical limit
  23. GRB 050915: IR Observations
  24. GRB 050915: Swift XRT refined analysis
  25. GRB 050915: Swift-BAT refined analysis
  26. GRB050915, optical observations
  27. GRB050915: XRT position
  28. GRB 050915: ROTSE-III optical limits
  29. GRB 050915: Swift detection of a GRB
  30. GRB050911: Upper limit on X-ray afterglow
  31. Swift-BAT trigger 155072 ground analysis
  32. Swift-BAT trigger 155072 is probably not a GRB
  33. GRB050914: XRT position probably due to cosmic ray
  34. Swift is in normal operation
  35. GRB050911: Swift UVOT followup observations
  36. GRB 050911, optical content of Swift/XRT error box
  37. GRB050911: Swift-XRT position
  38. GRB 050911, optical observations
  39. GRB 050911: Swift-BAT refined analysis
  40. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  41. GRB050911: Swift-BAT detection of a long burst
  42. GRB050908: detection of Swift/UVOT optical counterpart
  43. RBO GRB 050908 observations
  44. WIRO observations in I of GRB 050908
  45. GRB 050906: Possible X-ray Counterpart
  46. GRB050908: Swift/UVOT Early upper limits
  47. GRB050908 : Swift-XRT refined analysis
  48. GRB 050908: Swift-BAT refined analysis
  49. GRB 050908: Optical observations
  50. Gemini Spectroscopy of GRB 050908
  51. GRB 050908 : Swift XRT position
  52. GRB 050908: KAIT observations
  53. GRB 050908: P60 Confirmation of Optical Afterglow
  54. GRB 050908: Swift detection of a burst
  55. Swift trigger 154073 is not a GRB
  56. GRB050904: CrAO optical observations
  57. GRB 050904 BAT refined analysis of complete data set
  58. GRB 050906: MARGE Optical Limits
  59. GRB 050906: Swift-BAT refined analysis
  60. GRB 050906: Swift XRT upper limit
  61. GRB050906: P60 Observations
  62. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  63. GRB 050906: Bright galaxy in BAT error box
  64. GRB 050906: Swift/BAT Detection of a possible burst
  65. GRB 050904: Swift/UVOT observations
  66. GRB 050904: early Swift XRT analysis results
  67. GRB 050904: BAT refined analysis of partial data set
  68. GRB050904: P60 Observations
  69. GRB 050904: TAROT optical limits
  70. GRB050904: Swift-BAT detection of a probable burst
  71. Swift-BAT triggers 153461-153465 are not GRBs
  72. Retraction of Swift-BAT trigger #153355
  73. GRB 050824: MDM Observations
  74. GRB 050827: Swift XRT preliminary analysis results
  75. Swift Trigger #152652 is not a GRB
  76. GRB050827: Swift/UVOT upper limits
  77. GRB 050827: Optical Limit
  78. GRB 050827: XRT possible afterglow detection
  79. GRB050827: RTT150 optical observations
  80. GRB 050827: Swift-BAT refined analysis
  81. GRB050827: Swift-BAT detection of a burst
  82. GRB 050826: Optical Candidate
  83. GRB050824, HETE-2 Observation
  84. GRB 050826: Swift XRT preliminary analysis results
  85. GRB 050826: BAT refined analysis
  86. GRB050826: Swift/UVOT early upper limits
  87. GRB050824: First 2 hours of power low optical decay?
  88. GRB 050826: Swift XRT position
  89. GRB050826: Swift-BAT detection of a long burst
  90. GRB050824: MASTER final analysis of the OT observations
  91. Possible GRB050825:MASTER optical observations
  92. Swift-BAT trigger 152038 is definitely not a GRB
  93. GRB050824: CORRECTION to UVOT observing times
  94. Swift-BAT trigger 152038 is probably not a GRB
  95. GRB050824: Swift/UVOT detection of fading afterglow
  96. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  97. GRB050824, I-band imaging
  98. GRB 050822: refined XRT analysis
  99. GRB 050824: XRT refined analysis and possible afterglow detection
  100. GRB 050824: BAT refined analysis of a soft weak burst

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