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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"

20883 results found.

  1. GRB 051210: Swift detection of a burst
  2. IPN observations of SGR1806-20
  3. Swift XRT positions
  4. An extraordinary long burst on December 3 from SGR1806-20
  5. Possible resuming of the SGR 1806-20 activity
  6. GRB051117B: optical observation
  7. GRB051111: optical observaion
  8. GRB 051127: Swift-BAT detection of a possible burst
  9. GRB051117B: Swift XRT refined analysis
  10. GRB051117b: No Swift/UVOT Detection
  11. GRB 051117A: Swift/UVOT Detection of an Afterglow
  12. GRB 051109B: GAO 150cm telescope Optical limit
  13. GRB 051117A and B: Radio Observations
  14. GRB 051117B: R and I observations of possible host galaxy
  15. GRB 051117b: NIR observations
  16. GRB 051117B,optical observation
  17. GRB 051117B: Lulin R and I band observation
  18. GRB 051117B: ROTSE-III Optical Limits
  19. GRB 051117B: Swift detection of a burst
  20. GRB 051117: Swift detection of a bright burst
  21. GRB051114: results of the Swift-XRT observation
  22. GRB 051109B : Nainital upper limits
  23. GRB 051114: Radio Observations
  24. GRB050925: analysis of the XMM-Newton observation
  25. GRB 051114: Swift-BAT detection of a short burst
  26. GRB 051111: Further spectroscopic analysis
  27. GRB 051111: Radio afterglow
  28. GRB 051113: Swift-BAT detection of a burst
  29. GRB051103: Radio Observations
  30. GRB 051109A Milagro GeV/TeV Observations
  31. GRB051111: Swift/UVOT Observations
  32. GRB 051109A Optical Observations
  33. GRB 051111a: IR photometry
  34. GRB051111: Swift-BAT detection of a bright burst
  35. GRB 051109B. Radio Observations
  36. GRB 051109A
  37. GRB051109A - radio observations
  38. GRB 051109b: GETS observation
  39. GRB 051109B: ROTSE-III Optical Limits
  40. GRB 051109A: Swift-UVOT Observations
  41. GRB051109B: no UVOT source detected
  42. GRB 051109B : Lulin Optical Observations
  43. GRB 051109B: Super-LOTIS Observations
  44. GRB 051109B Kiso optical follow-up observation
  45. GRB051105B: REM Optical observation
  46. GRB 051109B: Swift detection of a burst
  47. GRB 051109: PROMPT Detections
  48. GRB 051109: Rc and Ic observations
  49. GRB 051109a: IR Photometry and Astrometry
  50. GRB051109: Swift detection of a burst
  51. GRB 051109a: IR Detections
  52. GRB051105B: Swift/XRT upper limit
  53. GRB051105B: Swift/UVOT upper limit
  54. GRB051103: optical observations
  55. GRB 051105a, observation from Naini Tal and OSN
  56. GRB 051105a: MDM Observations
  57. GRB 051105A: TNG optical observations
  58. GRB051105A: Swift/UVOT Observations
  59. GRB 051105A, radio observations
  60. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  61. XRT observations of GRB 051105A
  62. GRB 051105: Optical limit
  63. GRB 051105: Swift detection of a short burst
  64. Recent GRB UBVRcIc field photometry
  65. GRB051028 SARA Observation
  66. GRB051028: Swift/UVOT upper limits
  67. GRB051028: Swift XRT Position
  68. GRB051022: Swift XRT measurement of jet break
  69. GRB051021B: Swift/UVOT Upper limits
  70. GRB 051021, Optical Observations
  71. GRB051012: Swift-XRT analysis
  72. GRB 051022, mm counterpart
  73. GRB 051022: Swift/UVOT Upper Limits
  74. GRB051022: Radio Counterpart
  75. GRB051022: IR observations
  76. GRB051021A: Swift XRT refined analysis
  77. GRB051022: Optical Observations
  78. GRB 051021: PROMPT RcIc Observations
  79. GRB051021b: Magellan IR Imaging
  80. GRB051022: Swift XRT Position
  81. GRB 051021: P200 Ks Observations
  82. IPN triangulation of GRB051022 (=H3950)
  83. GRB 051022 (=H3950): SXC Flight Localization is Valid
  84. GRB051021: Swift/UVOT Upper Limits
  85. GRB 051021B: Refined analysis of the Swift-BAT burst
  86. GRB 051022: SSO40 Optical Observations
  87. GRB051022,optical observation
  88. GRB 051022A: ROTSE-III Optical Limits
  89. GRB 051021,optical observation
  90. GRB 051021B: Swift detection of a burst
  91. GRB051021: Swift XRT analysis
  92. Swift-BAT triggered on a posible CR Shower or possible GRB
  93. GRB 050502b: Optical limit
  94. Afterglow candidate of GRB 051016B observed at Lulin
  95. GRB 051016A: Swift/UVOT upper limits
  96. GRB 051016B: Swift/UVOT detection
  97. GRB 051016B,optical observation
  98. GRB 051016B : Optical follow-up at Lulin
  99. GRB 051016B: Swift detection of a soft burst
  100. GRB051016 XMM-Newton observation

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