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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"

19358 results found.

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

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