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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"

21393 results found.

  1. Swift-BAT detection of a possible burst
  2. GRB 051221: Discovery of fading optical afterglow
  3. GRB 051221: Swift XRT refined analysis
  4. GRB 051221: Swift/UVOT upper limits
  5. GRB 051221: No variability in Gemini data
  6. GRB 051221: Gemini observations
  7. GRB 051221: Improved astrometry of the IR counterpart
  8. GRB051221: K-band source
  9. GRB 051221: XRT position
  10. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  11. GRB 051221: Swift detection of a bright short burst
  12. Refined analysis of the SWIFT J1626.6-5156
  13. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  14. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  15. GRB 051211B: optical afterglow
  16. Swift detection of an RS CVn flare star
  17. Swift Trigger 172767 is not a GRB
  18. GRB 051215: Swift detection of a possible burst
  19. GRB 051215: A short GRB in a cluster?
  20. GRB051211B: Probable radio afterglow
  21. GRB051105: optical observations
  22. GRB 051213: Swift-BAT refined analysis
  23. GRB051211B: XRT refined analysis
  24. GRB 051213: Swift-BAT detection of a burst
  25. GRB 051211A: Swift/UVOT upper limits
  26. GRB 051211B: Swift/UVOT upper limits - correction
  27. GRB 051211B: Swift/UVOT upper limits
  28. GRB 051211B: Swift XRT confirmation of the afterglow
  29. GRB051211B: Liverpool Telescope observation
  30. GRB 051211b: RTT150 optical observations
  31. GRB051211b: P60 Observations
  32. GRB 051211B: Swift XRT Observations
  33. GRB 051210: Swift/UVOT upper limits
  34. GRB 051211: Swift XRT upper limit
  35. GRB 051210: Optical imaging from Las Campanas
  36. GRB 051210: SALT detection limit
  37. GRB 051210: BAT further refined analysis of the short burst
  38. GRB 051210: Swift XRT refined analysis
  39. GRB 051210: FRAM early limit
  40. GRB 051210: Swift-BAT refined analysis of a short burst
  41. GRB051210: Swift UVOT Observation
  42. GRB 051210: A short GRB in a cluster?
  43. GRB 051210: Swift detection of a burst
  44. IPN observations of SGR1806-20
  45. Swift XRT positions
  46. An extraordinary long burst on December 3 from SGR1806-20
  47. Swift UVOT Calibration Documentation
  48. GRB051117B: optical observation
  49. Swift-BAT trigger 165579 is not a GRB
  50. GRB 051127: Swift-BAT detection of a possible burst
  51. GRB051117B: Swift XRT refined analysis
  52. GRB051117b: No Swift/UVOT Detection
  53. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  54. GRB 051117A: Swift/UVOT Detection of an Afterglow
  55. GRB051111: Rc optical observations
  56. GRB051008: Suzaku WAM observation of the prompt emission
  57. GRB 051117B: MARGE Optical Limits
  58. GRB 051117A and B: Radio Observations
  59. GRB 051117B: R and I observations of possible host galaxy
  60. GRB 051117b: NIR observations
  61. GRB 051117A: Refined analysis of the Swift-BAT burst
  62. GRB 051117B: Refined analysis of the Swift-BAT burst
  63. GRB051117A : XRT refined analysis
  64. GRB 051117B,optical observation
  65. GRB 051117B: Lulin R and I band observation
  66. GRB 051117B: Optical observations
  67. GRB 051117B: ROTSE-III Optical Limits
  68. GRB051117B: Swift XRT position
  69. GRB 051117B: Swift detection of a burst
  70. GRB 051117: Swift detection of a bright burst
  71. GRB051114: results of the Swift-XRT observation
  72. GRB 051109B : Nainital upper limits
  73. GRB 051114: Swift-BAT refined analysis
  74. GRB050925: analysis of the XMM-Newton observation
  75. GRB 051114: Swift-BAT detection of a short burst
  76. GRB 051113: Swift-BAT refined analysis
  77. GRB 051113: Swift-BAT detection of a burst
  78. GRB 051111: AEOS optical observations
  79. GRB 051109A Milagro GeV/TeV Observations
  80. GRB/SGR 050925: XMM-Newton ToO observation
  81. GRB051111: Swift/UVOT Observations
  82. GRB051111: XRT preliminary analysis
  83. GRB 051111: Swift-BAT refined analysis
  84. GRB 051109A Optical Observations
  85. GRB051111a: SARA Observations
  86. GRB 051111A: KAIT optical observations
  87. GRB051111: Super-LOTIS Early Detection
  88. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  89. Faulkes Telescope R-band detection of GRB051111
  90. GRB051111: Swift-BAT detection of a bright burst
  91. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  92. GRB 051008 Tautenburg Supernova Search
  93. GRB 051109B. Radio Observations
  94. Early RAPTOR measurements of GRB 051109a - the movie.
  95. Konus-Wind observation of GRB 051109A
  96. GRB 051109B: Swift-BAT refined analysis
  97. GRB 051109B: ROTSE-III Optical Limits
  98. GRB 051109A: Swift-UVOT Observations
  99. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  100. GRB051109B: no UVOT source detected

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