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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"

28871 results found.

  1. GRB 061210, Swift-BAT refined analysis of the SHB
  2. GRB 061210: Swift-BAT detection of a short burst
  3. Optical Afterglow observations of GRB 061126
  4. GRB061126: update on the Swift-XRT afterglow light curve
  5. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  6. GRB 061202: TORTOREM optical upper limits
  7. GRB061126 : NMSU 1.0m observations
  8. GRB061202: FRAM early follow-up limit
  9. GRB061202 optical limit by "Pi of the Sky"
  10. Konus-Wind observation of GRB 061201
  11. GRB061202: optical/NIR observations with REM
  12. GRB061202: Swift/UVOT Upper Limits
  13. GRB 061202, Swift-BAT refined analysis
  14. GRB 061202: Swift detection of a burst
  15. GRB 061201: Swift XRT Team refined analysis
  16. GRB 061201: Initial UVOT Observations
  17. GRB 061201, Swift-BAT refined analysis of the SHB
  18. GRB 061201: Swift detection of a short hard burst
  19. GRB 061201: Coincidence with a Galaxy Cluster
  20. GRB 061122: GETS observation
  21. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  22. GRB 061126: Early Super-LOTIS Observations
  23. GRB 061126: optical observation
  24. GRB061126: Optical afterglow observations from MIRO
  25. GRB061126: Optical afterglow observations from MIRO
  26. GRB 061126: Swift-XRT refined analysis
  27. GRB 061126: Swift/UVOT Observations
  28. GRB 061126, Swift-BAT refined analysis
  29. GRB 061126: SARA Observations
  30. GRB 061126: Early Detection of the IR Afterglow
  31. GRB 061126: Faulkes Telescope North Optical Observations
  32. GRB 061126: Swift/UVOT Afterglow Detection
  33. GRB 061126: XRT position
  34. GRB 061126: Swift detection of a burst
  35. GRB 061121: Ep,i - Eiso correlation
  36. GRB061122: Swift/UVOT Optical Observations
  37. GRB 061121: ART detection in Ic
  38. GRB061122: Swift-XRT position
  39. Konus-Wind and Konus-A observations of GRB 061121
  40. Swift-BAT trigger 239987 is not a GRB
  41. GRB 061121: Swift/UVOT Observations
  42. GRB 061121: Swift-XRT Team Refined Analysis
  43. GRB 061121, Swift-BAT refined analysis
  44. GRB061121, optical observation
  45. GRB 061121: Faulkes Telescope North Optical Observation
  46. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  47. GRB 061121: Swift detection of a bright burst with an optical counterpart
  48. GRB 060111B: Swift UVOT Refined Magnitudes
  49. GRB 061110B: NIR Observations
  50. Swift/UVOT Upper Limits for GRB061110b
  51. Swift/UVOT Upper Limits for GRB061110a
  52. GRB 061110B, Swift-BAT refined analysis
  53. GRB061110B: Optical observations at Crni Vrh
  54. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  55. GRB 061110B: Swift-UVOT Initial Observation
  56. GRB 061110A, Swift-BAT refined analysis
  57. GRB 061110B: TAROT Calern observatory optical observations
  58. GRB 061110B: Swift detection of a burst
  59. GRB 061110: ROTSE-III Optical Limits
  60. GRB 061110: Swift detection of a burst
  61. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  62. GRB 061109: optical observation
  63. GRB 061109: TAROT Calern observatory optical observations
  64. GRB 061109: Swift detection of a possible burst
  65. GRB 061027: TAROT La Silla observatory optical observations
  66. GRB 061102: Swift/UVOT Magnitude Upper Limits
  67. GRB 061102, XRT refined analysis
  68. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  69. GRB061102B: Super-LOTIS observations
  70. GRB 061028: Optical R passband observations
  71. GRB 061102B: Swift detection of a possible burst
  72. GRB 061102, Swift-BAT refined analysis
  73. GRB 061102: Swift detection of a burst
  74. GRB 061028: MDM Observations
  75. GRB 061028: SARA upper limit
  76. GRB 061028: z band imaging
  77. GRB061028: XRT refined analysis
  78. GRB 061028: Swift/UVOT Observations
  79. GRB 061028, Swift-BAT refined analysis
  80. GRB 061028: TAROT Calern observatory late optical observations
  81. GRB 061028: TAROT Calern observatory optical observations
  82. GRB 061028: Swift detection of a burst
  83. GRB 061027, Swift refined analysis of a possible burst
  84. GRB 061027: Swift detection of a possible burst
  85. GRB061025: Swift XRT refined analysis
  86. GRB061025: Swift/UVOT observations
  87. GRB 061019: MITSuME upper limits
  88. GRB 061025: ROTSE-III Optical Limits
  89. GRB 061021, Swift-BAT Lag analysis
  90. Konus-Wind observation of GRB 061021
  91. GRB 061021: Swift-XRT refined analysis
  92. GRB 061021: Swift/UVOT Observation
  93. GRB 061021, Swift-BAT refined analysis
  94. GRB 061021: Swift detection of a burst
  95. GRB 061019: Super-LOTIS upper limit
  96. GRB 061019: SARA upper limit
  97. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  98. GRB 061019: Swift/UVOT upper limit
  99. GRB 061019, Swift-BAT refined analysis
  100. GRB 061019: TAROT La Silla observatory optical observations

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