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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"

28885 results found.

  1. GRB 061217, Further Swift-BAT refined analysis of the short hard burst
  2. GRB 061217, Swift-BAT refined analysis
  3. GRB 061217: REM prompt observations
  4. GRB 061217: ROTSE-III Optical Limits
  5. GRB 061217: Swift detection of a short hard burst
  6. GRB061210: Swift/UVOT observations
  7. Swift-BAT Trigger 250908 is a Cosmic Ray Shower event
  8. GRB 061210: Swift XRT analysis - Possible counterparts
  9. GRB 061210 : Faulkes North Telescope optical limit
  10. GRB 061214(?): ROTSE-III Optical Limits
  11. GRB 061214(?): Swift detection of a possible burst
  12. Swift/BAT trigger #250033 is due to a known source during loss of
  13. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  14. GRB 061213: MASTER-VWF-Kislovodsk observations
  15. GRB 061210, Swift-BAT refined analysis of the SHB
  16. GRB 061210: Swift-BAT detection of a short burst
  17. Optical Afterglow observations of GRB 061126
  18. GRB061126: update on the Swift-XRT afterglow light curve
  19. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  20. GRB 061202: TORTOREM optical upper limits
  21. GRB061126 : NMSU 1.0m observations
  22. GRB061202: FRAM early follow-up limit
  23. GRB061202 optical limit by "Pi of the Sky"
  24. Konus-Wind observation of GRB 061201
  25. GRB061202: optical/NIR observations with REM
  26. GRB061202: Swift/UVOT Upper Limits
  27. GRB 061202, Swift-BAT refined analysis
  28. GRB 061202: Swift detection of a burst
  29. GRB 061201: Swift XRT Team refined analysis
  30. GRB 061201: Initial UVOT Observations
  31. GRB 061201, Swift-BAT refined analysis of the SHB
  32. GRB 061201: Swift detection of a short hard burst
  33. GRB 061201: Coincidence with a Galaxy Cluster
  34. GRB 061122: GETS observation
  35. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  36. GRB 061126: Early Super-LOTIS Observations
  37. GRB 061126: optical observation
  38. GRB061126: Optical afterglow observations from MIRO
  39. GRB061126: Optical afterglow observations from MIRO
  40. GRB 061126: Swift-XRT refined analysis
  41. GRB 061126: Swift/UVOT Observations
  42. GRB 061126, Swift-BAT refined analysis
  43. GRB 061126: SARA Observations
  44. GRB 061126: Early Detection of the IR Afterglow
  45. GRB 061126: Faulkes Telescope North Optical Observations
  46. GRB 061126: Swift/UVOT Afterglow Detection
  47. GRB 061126: XRT position
  48. GRB 061126: Swift detection of a burst
  49. GRB 061121: Ep,i - Eiso correlation
  50. GRB061122: Swift/UVOT Optical Observations
  51. GRB 061121: ART detection in Ic
  52. GRB061122: Swift-XRT position
  53. Konus-Wind and Konus-A observations of GRB 061121
  54. Swift-BAT trigger 239987 is not a GRB
  55. GRB 061121: Swift/UVOT Observations
  56. GRB 061121: Swift-XRT Team Refined Analysis
  57. GRB 061121, Swift-BAT refined analysis
  58. GRB061121, optical observation
  59. GRB 061121: Faulkes Telescope North Optical Observation
  60. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  61. GRB 061121: Swift detection of a bright burst with an optical counterpart
  62. GRB 060111B: Swift UVOT Refined Magnitudes
  63. GRB 061110B: NIR Observations
  64. Swift/UVOT Upper Limits for GRB061110b
  65. Swift/UVOT Upper Limits for GRB061110a
  66. GRB 061110B, Swift-BAT refined analysis
  67. GRB061110B: Optical observations at Crni Vrh
  68. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  69. GRB 061110B: Swift-UVOT Initial Observation
  70. GRB 061110A, Swift-BAT refined analysis
  71. GRB 061110B: TAROT Calern observatory optical observations
  72. GRB 061110B: Swift detection of a burst
  73. GRB 061110: ROTSE-III Optical Limits
  74. GRB 061110: Swift detection of a burst
  75. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  76. GRB 061109: optical observation
  77. GRB 061109: TAROT Calern observatory optical observations
  78. GRB 061109: Swift detection of a possible burst
  79. GRB 061027: TAROT La Silla observatory optical observations
  80. GRB 061102: Swift/UVOT Magnitude Upper Limits
  81. GRB 061102, XRT refined analysis
  82. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  83. GRB061102B: Super-LOTIS observations
  84. GRB 061028: Optical R passband observations
  85. GRB 061102B: Swift detection of a possible burst
  86. GRB 061102, Swift-BAT refined analysis
  87. GRB 061102: Swift detection of a burst
  88. GRB 061028: MDM Observations
  89. GRB 061028: SARA upper limit
  90. GRB 061028: z band imaging
  91. GRB061028: XRT refined analysis
  92. GRB 061028: Swift/UVOT Observations
  93. GRB 061028, Swift-BAT refined analysis
  94. GRB 061028: TAROT Calern observatory late optical observations
  95. GRB 061028: TAROT Calern observatory optical observations
  96. GRB 061028: Swift detection of a burst
  97. GRB 061027, Swift refined analysis of a possible burst
  98. GRB 061027: Swift detection of a possible burst
  99. GRB061025: Swift XRT refined analysis
  100. GRB061025: Swift/UVOT observations

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