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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"

18525 results found.

  1. Swift-BAT trigger 160640 is not a real GRB
  2. Swift-BAT trigger 160619 is not a GRB
  3. Swift-BAT triggered on a posible CR Shower or possible GRB
  4. GRB 051016A: Swift/UVOT upper limits
  5. GRB 051016B: refined analysis of the Swift/XRT data
  6. GRB 051016B: Swift/UVOT detection
  7. GRB 051016B : Optical follow-up at Lulin
  8. GRB 051016B: Refined analysis of the Swift-BAT burst
  9. GRB 051016B: Swift detection of a soft burst
  10. GRB 051016: Swift-BAT refined analysis
  11. GRB051016 XMM-Newton observation
  12. GRB051016: Swift XRT refined analysis.
  13. GRB051016: Swift detection of a burst
  14. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  15. GRB 051012: Swift-BAT detection of burst yesterday
  16. Swift trigger 159578 is not a burst
  17. Swift-BAT Trigger 159578 is a possible burst
  18. GRB050805A: Rc optical observations
  19. GRB 051006: Swift/UVOT Upper Limits
  20. GRB 051008 - a low redshift low-luminosity burst?
  21. GRB051008: Swift XRT refined analysis
  22. GRB051008 - Swift UVOT upper limits
  23. Konus-Wind observation of GRB 051008
  24. GRB051008: Final refined analysis of the Swift-BAT burst
  25. GRB 051008: R-band upper limit
  26. GRB051008: Refined analysis of the Swift-BAT burst
  27. GRB 051008: Swift XRT position
  28. GRB 051008: early Swift XRT analysis
  29. GRB 051008: Swift UVOT Candidate
  30. GRB051008: Swift-BAT detection of a bright burst
  31. GRB 051006: XRT refined analysis
  32. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  33. GRB 051006: optical observations at Sierra Nevada
  34. GRB051006: Refined analysis of the Swift-BAT burst
  35. GRB 051006: XRT position
  36. GRB051006: Swift detection of a burst
  37. Swift-BAT triggers 158261 and 158262 Retraction
  38. GRB051001: Swift UVOT Upper Limits
  39. GRB 050925: Second Epoch WSRT Radio Observations
  40. GRB 051001: Swift XRT refined analysis
  41. GRB 051001, optical observations at Mt. John
  42. GRB 051001: I-band limit
  43. GRB 051001: Swift-BAT refined analysis
  44. GRB 051001: Swift Detection of a Burst
  45. GRB 051001: ROTSE-III Optical Limits
  46. GRB050922B: optical limit
  47. GRB050925: Swift/XRT limits
  48. GRB/SGR 050925: IR Observations
  49. GRB050922C - Swift UVOT preliminary analysis
  50. GRB 050925: WSRT Radio Observations
  51. GRB050925: Swift UVOT upper limits
  52. Refined analysis of the Swift-BAT soft short burst
  53. GRB050925: Faulkes Telescope North R-band limit
  54. GRB050925: Swift-BAT detection of a short burst
  55. GRB 050922B: Correction to BAT refined analysis, longer burst
  56. GRB050922B: refined XRT analysis
  57. Konus-Wind observation of GRB 050922C
  58. GRB050922B: Swift UVOT early upper limits.
  59. GRB 050922B: optical limit
  60. GRB 050922C: Swift XRT refined analysis
  61. HETE Fregate observations of GRB 050922C
  62. GRB 050922C: Swift-BAT refined analysis
  63. GRB 050922B: Swift-BAT refined analysis
  64. GRB050922C: optical observations
  65. GRB 050922C: Absorption redshift from the Nordic Optical Telescope
  66. GRB 050922C: optical obserations
  67. GRB 050922C: NOT optical observations
  68. GRB 050922A: Analysis of Swift/XRT TOO observation
  69. GRB 050922C: Swift detection of a bright burst
  70. GRB 050922C: ROTSE-IIId Refined Analysis
  71. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  72. GRB 050922B: ROTSE-III Optical Limits
  73. GRB 050922B,optical observation
  74. GRB050922B: Swift-BAT detection of a weak long burst
  75. GRB050918: Possible Swift/XRT detected afterglow
  76. GRB050820B: analysis of the XMM-Newton observation
  77. GRB050916: Swift/UVOT Upper Limits
  78. GRB 050916: Swift-BAT refined analysis
  79. Swift-BAT trigger 155764 is not a GRB
  80. Swift-BAT trigger 155764 is probably not a GRB
  81. Swift trigger 155764: bad XRT centroid
  82. Swift-BAT trigger 155535 is definitely not a GRB
  83. GRB050916 : Swift-XRT refined analysis
  84. GRB 050916: XRT position
  85. GRB 050915B: Swift-BAT refined analysis
  86. GRB 050915B: Swift/UVOT Upper Limits
  87. GRB050916: Swift-BAT detection of a long weak burst
  88. GRB 050915B: XRT position
  89. GRB050915B: Swift-BAT detection of a long bright burst
  90. GRB050915: Swift/UVOT upper limits
  91. GRB 050915: KAIT optical limit
  92. GRB 050915: IR Observations
  93. GRB 050915: Swift XRT refined analysis
  94. GRB 050915: Swift-BAT refined analysis
  95. GRB050915, optical observations
  96. GRB050915: XRT position
  97. GRB 050915: ROTSE-III optical limits
  98. GRB 050915: Swift detection of a GRB
  99. GRB050911: Upper limit on X-ray afterglow
  100. Swift-BAT trigger 155072 ground analysis

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