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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"

26228 results found.

  1. Swift-BAT trigger 155535 is definitely not a GRB
  2. GRB050916 : Swift-XRT refined analysis
  3. GRB 050916: XRT position
  4. GRB 050915B: Swift-BAT refined analysis
  5. GRB 050915B: Swift/UVOT Upper Limits
  6. GRB050916: Swift-BAT detection of a long weak burst
  7. GRB050915B: Swift-BAT detection of a long bright burst
  8. GRB050915: Swift/UVOT upper limits
  9. GRB 050915: KAIT optical limit
  10. GRB 050915: IR Observations
  11. GRB 050915: Swift XRT refined analysis
  12. GRB 050915: Swift-BAT refined analysis
  13. GRB050915: XRT position
  14. GRB 050915: ROTSE-III optical limits
  15. GRB 050915: Swift detection of a GRB
  16. GRB050911: Upper limit on X-ray afterglow
  17. Swift-BAT trigger 155072 ground analysis
  18. Swift-BAT trigger 155072 is probably not a GRB
  19. GRB050914: XRT position probably due to cosmic ray
  20. Swift is in normal operation
  21. GRB050911: Swift UVOT followup observations
  22. GRB050911: Swift-XRT position
  23. GRB 050911: Swift-BAT refined analysis
  24. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  25. GRB050911: Swift-BAT detection of a long burst
  26. GRB050908: detection of Swift/UVOT optical counterpart
  27. GRB 050910a: TAROT early optical limits
  28. GRB050908: Swift/UVOT Early upper limits
  29. GRB050908 : Swift-XRT refined analysis
  30. GRB 050908: Swift-BAT refined analysis
  31. GRB 050908: Optical observations
  32. Gemini Spectroscopy of GRB 050908
  33. GRB 050908 : Swift XRT position
  34. GRB 050908: KAIT observations
  35. GRB 050908: Swift detection of a burst
  36. Swift trigger 154073 is not a GRB
  37. GRB 050906: MARGE Optical Limits
  38. GRB 050906: Swift-BAT refined analysis
  39. GRB050906: P60 Observations
  40. GRB 050906: Bright galaxy in BAT error box
  41. GRB 050906: Swift/BAT Detection of a possible burst
  42. GRB 050904: Swift/UVOT observations
  43. GRB 050904: early Swift XRT analysis results
  44. GRB 050904: BAT refined analysis of partial data set
  45. GRB050904: P60 Observations
  46. GRB 050904: TAROT optical limits
  47. GRB050904: Swift-BAT detection of a probable burst
  48. Swift-BAT triggers 153461-153465 are not GRBs
  49. Retraction of Swift-BAT trigger #153355
  50. Swift Trigger #152652 is not a GRB
  51. GRB050827: Swift/UVOT upper limits
  52. GRB 050827: Optical Limit
  53. GRB050820A: RTT150 optical observations
  54. GRB050827: RTT150 optical observations
  55. GRB 050827: Swift-BAT refined analysis
  56. GRB050827: Swift-BAT detection of a burst
  57. GRB 050826: Optical Candidate
  58. GRB 050826: Swift XRT preliminary analysis results
  59. GRB 050826: BAT refined analysis
  60. GRB050826: Swift/UVOT early upper limits
  61. GRB 050826: Swift XRT position
  62. GRB050826: Swift-BAT detection of a long burst
  63. GRB050824: MASTER final analysis of the OT observations
  64. Possible GRB050825:MASTER optical observations
  65. Swift-BAT trigger 152038 is definitely not a GRB
  66. GRB050824: CORRECTION to UVOT observing times
  67. Swift-BAT trigger 152038 is probably not a GRB
  68. GRB050824: Swift/UVOT detection of fading afterglow
  69. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  70. GRB 050824: XRT refined analysis and possible afterglow detection
  71. GRB 050824: BAT refined analysis of a soft weak burst
  72. GRB050824: MASTER:OT decay
  73. GRB050824: MASTER observation OT
  74. GRB050805a: MASTER optical candidat
  75. GRB 050824: ROTSE-III Optical Limits
  76. GRB050824: Swift-BAT detection of a burst
  77. GRB050820A: RTT150 optical observations
  78. VLT/UVES spectroscopy of GRB050820
  79. GRB050822: Swift/UVOT upper limits
  80. GRB 050822: Swift-BAT refined analysis
  81. GRB 050820a - corrections to GCN 3846
  82. Swift/UVOT UV Photometry of GRB 050820B
  83. GRB 050822: ROTSE-III Prompt Optical Limits
  84. GRB 050822: Swift detection of a long burst
  85. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  86. GRB 050820a: NIR Observations by WIRO
  87. GRB 050820B: Swift XRT position
  88. GRB050820B: Refined analysis of the Swift-BAT burst
  89. GRB050820B: BAT-Swift detection of a bright GRB
  90. Swift/UVOT photometry of GRB050820
  91. GRB050820: refined XRT analysis
  92. GRB 050820: Early RAPTOR detections
  93. GRB 050820 Swift-BAT refined analysis
  94. GRB050819: refined XRT analysis
  95. GRB 050820: Swift detection of a GRB
  96. GRB050820: Optical afterglow from P60
  97. GRB 050819 Swift-BAT refined analysis
  98. GRB050819: Swift XRT position
  99. GRB050819: Swift-BAT detection of a weak burst
  100. Swift-BAT trigger 150993 is not a GRB

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