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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"

19542 results found.

  1. GRB051109B: no UVOT source detected
  2. GRB 051109B: Super-LOTIS Observations
  3. GRB051105B: REM Optical observation
  4. GRB 051109: Rc and Ic observations
  5. GRB 051109a: IR Photometry and Astrometry
  6. GRB051109: Swift detection of a burst
  7. GRB 051109a: IR Detections
  8. GRB051105B: Swift/XRT upper limit
  9. GRB051105B: Swift/UVOT upper limit
  10. GRB051103: optical observations
  11. GRB 051105a, observation from Naini Tal and OSN
  12. GRB 051105a: MDM Observations
  13. GRB 051105A: TNG optical observations
  14. GRB051105A: Swift/UVOT Observations
  15. GRB 051105A, radio observations
  16. XRT observations of GRB 051105A
  17. GRB 051105: Swift-BAT improved refined analysis
  18. GRB 051105: Swift detection of a short burst
  19. Recent GRB UBVRcIc field photometry
  20. GRB051028 SARA Observation
  21. GRB051028: Swift/UVOT upper limits
  22. GRB051028: Swift XRT Position
  23. SGR 1806-20: continued moderate activity seen with INTEGRAL
  24. GRB051021B: Swift/UVOT Upper limits
  25. GRB 051021, Optical Observations
  26. GRB051012: Swift-XRT analysis
  27. GRB 051022: Swift/UVOT Upper Limits
  28. GRB051022: Radio Counterpart
  29. GRB051022: IR observations
  30. GRB051021A: Swift XRT refined analysis
  31. GRB051022: Optical Observations
  32. GRB051021b: Magellan IR Imaging
  33. GRB051022: Swift XRT Position
  34. GRB 051021: P200 Ks Observations
  35. GRB 051022 (=H3950): SXC Flight Localization is Valid
  36. GRB051021: Swift/UVOT Upper Limits
  37. GRB 051022: SSO40 Optical Observations
  38. GRB051022,optical observation
  39. GRB 051021,optical observation
  40. GRB 051021B: Swift detection of a burst
  41. Swift-BAT triggered on a posible CR Shower or possible GRB
  42. Afterglow candidate of GRB 051016B observed at Lulin
  43. GRB 051016A: Swift/UVOT upper limits
  44. GRB 051016B: refined analysis of the Swift/XRT data
  45. GRB 051016B: Swift/UVOT detection
  46. GRB 051016B,optical observation
  47. GRB 051016B: Swift detection of a soft burst
  48. GRB051016 XMM-Newton observation
  49. GRB051016: Swift XRT refined analysis.
  50. GRB 051016: PROMPT Observations
  51. GRB051016: Swift detection of a burst
  52. GRB051006: optical observations
  53. GRB 051012: Swift-BAT detection of burst yesterday
  54. GRB 051006: Swift/UVOT Upper Limits
  55. GRB051008: optical candidate
  56. GRB051008: optical observation
  57. GRB051008: Radio Observation
  58. GRB 051008: Swift XRT position
  59. GRB 051008, optical observations
  60. GRB 051008: early Swift XRT analysis
  61. GRB 051008: Swift UVOT Candidate
  62. GRB 051006: P60 Observations
  63. GRB 051006: XRT refined analysis
  64. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  65. GRB051006: Refined analysis of the Swift-BAT burst
  66. GRB 051006: XRT position
  67. GRB051006: Swift detection of a burst
  68. GRB 050906, summary of radio observations
  69. GRB051001: Swift UVOT Upper Limits
  70. GRB 051001, optical observations at Mt. John
  71. GRB 051001: AAT infra-red observations
  72. GRB 051001: Swift Detection of a Burst
  73. GRB050908: optical observations
  74. GRB 050820A: NIR photometry at the TNG
  75. GRB/SGR 050925: IR Observations
  76. GRB050925: Swift UVOT upper limits
  77. Refined analysis of the Swift-BAT soft short burst
  78. GRB050925: Faulkes Telescope North R-band limit
  79. GRB050925: Swift-BAT detection of a short burst
  80. GRB050922B: Swift UVOT early upper limits.
  81. INT 2.5m limit for GRB050922B
  82. GRB 050922C: Swift XRT refined analysis
  83. GRB 050922C: Swift-BAT refined analysis
  84. GRB 050922C: optical obserations
  85. GRB 050922C: NOT optical observations
  86. GRB 050922C: Swift detection of a bright burst
  87. GRB 050922B: ROTSE-III Optical Limits
  88. GRB 050922B,optical observation
  89. GRB050922B: Swift-BAT detection of a weak long burst
  90. GRB050820B: analysis of the XMM-Newton observation
  91. GRB050916: Swift/UVOT Upper Limits
  92. Swift-BAT trigger 155764 is not a GRB
  93. Swift-BAT trigger 155764 is probably not a GRB
  94. Swift trigger 155764: bad XRT centroid
  95. Swift-BAT trigger 155535 is definitely not a GRB
  96. GRB050916 : Swift-XRT refined analysis
  97. GRB 050916: XRT position
  98. GRB 050915B: Swift-BAT refined analysis
  99. GRB 050915B: Swift/UVOT Upper Limits
  100. GRB 050915a: IR Transient

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