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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"

27032 results found.

  1. GRB 050916: Swift-BAT refined analysis
  2. Swift-BAT trigger 155764 is not a GRB
  3. Swift-BAT trigger 155764 is probably not a GRB
  4. Swift trigger 155764: bad XRT centroid
  5. Swift-BAT trigger 155535 is definitely not a GRB
  6. GRB050916 : Swift-XRT refined analysis
  7. GRB 050916: XRT position
  8. GRB 050915B: Swift-BAT refined analysis
  9. GRB 050915B: Swift/UVOT Upper Limits
  10. GRB050916: Swift-BAT detection of a long weak burst
  11. GRB050915B: Swift-BAT detection of a long bright burst
  12. GRB050915: Swift/UVOT upper limits
  13. GRB 050915: KAIT optical limit
  14. GRB 050915: IR Observations
  15. GRB 050915: Swift XRT refined analysis
  16. GRB 050915: Swift-BAT refined analysis
  17. GRB050915: XRT position
  18. GRB 050915: ROTSE-III optical limits
  19. GRB 050915: Swift detection of a GRB
  20. GRB050911: Upper limit on X-ray afterglow
  21. Swift-BAT trigger 155072 ground analysis
  22. Swift-BAT trigger 155072 is probably not a GRB
  23. GRB050914: XRT position probably due to cosmic ray
  24. Swift is in normal operation
  25. GRB050911: Swift UVOT followup observations
  26. GRB050911: Swift-XRT position
  27. GRB 050911: Swift-BAT refined analysis
  28. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  29. GRB050911: Swift-BAT detection of a long burst
  30. GRB050908: detection of Swift/UVOT optical counterpart
  31. GRB 050910a: TAROT early optical limits
  32. GRB050908: Swift/UVOT Early upper limits
  33. GRB050908 : Swift-XRT refined analysis
  34. GRB 050908: Swift-BAT refined analysis
  35. GRB 050908: Optical observations
  36. Gemini Spectroscopy of GRB 050908
  37. GRB 050908 : Swift XRT position
  38. GRB 050908: KAIT observations
  39. GRB 050908: Swift detection of a burst
  40. Swift trigger 154073 is not a GRB
  41. GRB 050906: MARGE Optical Limits
  42. GRB 050906: Swift-BAT refined analysis
  43. GRB050906: P60 Observations
  44. GRB 050906: Bright galaxy in BAT error box
  45. GRB 050906: Swift/BAT Detection of a possible burst
  46. GRB 050904: Swift/UVOT observations
  47. GRB 050904: early Swift XRT analysis results
  48. GRB 050904: BAT refined analysis of partial data set
  49. GRB050904: P60 Observations
  50. GRB 050904: TAROT optical limits
  51. GRB050904: Swift-BAT detection of a probable burst
  52. Swift-BAT triggers 153461-153465 are not GRBs
  53. Retraction of Swift-BAT trigger #153355
  54. Swift Trigger #152652 is not a GRB
  55. GRB050827: Swift/UVOT upper limits
  56. GRB 050827: Optical Limit
  57. GRB050820A: RTT150 optical observations
  58. GRB050827: RTT150 optical observations
  59. GRB 050827: Swift-BAT refined analysis
  60. GRB050827: Swift-BAT detection of a burst
  61. GRB 050826: Optical Candidate
  62. GRB 050826: Swift XRT preliminary analysis results
  63. GRB 050826: BAT refined analysis
  64. GRB050826: Swift/UVOT early upper limits
  65. GRB 050826: Swift XRT position
  66. GRB050826: Swift-BAT detection of a long burst
  67. GRB050824: MASTER final analysis of the OT observations
  68. Possible GRB050825:MASTER optical observations
  69. Swift-BAT trigger 152038 is definitely not a GRB
  70. GRB050824: CORRECTION to UVOT observing times
  71. Swift-BAT trigger 152038 is probably not a GRB
  72. GRB050824: Swift/UVOT detection of fading afterglow
  73. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  74. GRB 050824: XRT refined analysis and possible afterglow detection
  75. GRB 050824: BAT refined analysis of a soft weak burst
  76. GRB050824: MASTER:OT decay
  77. GRB050824: MASTER observation OT
  78. GRB050805a: MASTER optical candidat
  79. GRB 050824: ROTSE-III Optical Limits
  80. GRB050824: Swift-BAT detection of a burst
  81. GRB050820A: RTT150 optical observations
  82. VLT/UVES spectroscopy of GRB050820
  83. GRB050822: Swift/UVOT upper limits
  84. GRB 050822: Swift-BAT refined analysis
  85. GRB 050820a - corrections to GCN 3846
  86. Swift/UVOT UV Photometry of GRB 050820B
  87. GRB 050822: ROTSE-III Prompt Optical Limits
  88. GRB 050822: Swift detection of a long burst
  89. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  90. GRB 050820a: NIR Observations by WIRO
  91. GRB 050820B: Swift XRT position
  92. GRB050820B: Refined analysis of the Swift-BAT burst
  93. GRB050820B: BAT-Swift detection of a bright GRB
  94. Swift/UVOT photometry of GRB050820
  95. GRB050820: refined XRT analysis
  96. GRB 050820: Early RAPTOR detections
  97. GRB 050820 Swift-BAT refined analysis
  98. GRB050819: refined XRT analysis
  99. GRB 050820: Swift detection of a GRB
  100. GRB050820: Optical afterglow from P60

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