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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"

18633 results found.

  1. GRB 050915: Swift XRT refined analysis
  2. GRB 050915: Swift-BAT refined analysis
  3. GRB050915, optical observations
  4. GRB050915: XRT position
  5. GRB 050915: ROTSE-III optical limits
  6. GRB 050915: Swift detection of a GRB
  7. GRB050911: Upper limit on X-ray afterglow
  8. Swift-BAT trigger 155072 ground analysis
  9. Swift-BAT trigger 155072 is probably not a GRB
  10. GRB050914: XRT position probably due to cosmic ray
  11. Swift is in normal operation
  12. GRB050911: Swift UVOT followup observations
  13. GRB 050911, optical content of Swift/XRT error box
  14. GRB050911: Swift-XRT position
  15. GRB 050911, optical observations
  16. GRB 050911: Swift-BAT refined analysis
  17. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  18. GRB050911: Swift-BAT detection of a long burst
  19. GRB050908: detection of Swift/UVOT optical counterpart
  20. RBO GRB 050908 observations
  21. WIRO observations in I of GRB 050908
  22. GRB 050906: Possible X-ray Counterpart
  23. GRB050908: Swift/UVOT Early upper limits
  24. GRB050908 : Swift-XRT refined analysis
  25. GRB 050908: Swift-BAT refined analysis
  26. GRB 050908: Optical observations
  27. Gemini Spectroscopy of GRB 050908
  28. GRB 050908 : Swift XRT position
  29. GRB 050908: KAIT observations
  30. GRB 050908: P60 Confirmation of Optical Afterglow
  31. GRB 050908: Swift detection of a burst
  32. Swift trigger 154073 is not a GRB
  33. GRB050904: CrAO optical observations
  34. GRB 050904 BAT refined analysis of complete data set
  35. GRB 050906: MARGE Optical Limits
  36. GRB 050906: Swift-BAT refined analysis
  37. GRB 050906: Swift XRT upper limit
  38. GRB050906: P60 Observations
  39. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  40. GRB 050906: Bright galaxy in BAT error box
  41. GRB 050906: Swift/BAT Detection of a possible burst
  42. GRB 050904: Swift/UVOT observations
  43. GRB 050904: early Swift XRT analysis results
  44. GRB 050904: BAT refined analysis of partial data set
  45. GRB050904: P60 Observations
  46. GRB 050904: TAROT optical limits
  47. GRB050904: Swift-BAT detection of a probable burst
  48. Swift-BAT triggers 153461-153465 are not GRBs
  49. Retraction of Swift-BAT trigger #153355
  50. GRB 050824: MDM Observations
  51. GRB 050827: Swift XRT preliminary analysis results
  52. Swift Trigger #152652 is not a GRB
  53. GRB050827: Swift/UVOT upper limits
  54. GRB 050827: Optical Limit
  55. GRB 050827: XRT possible afterglow detection
  56. GRB050827: RTT150 optical observations
  57. GRB 050827: Swift-BAT refined analysis
  58. GRB050827: Swift-BAT detection of a burst
  59. GRB 050826: Optical Candidate
  60. GRB050824, HETE-2 Observation
  61. GRB 050826: Swift XRT preliminary analysis results
  62. GRB 050826: BAT refined analysis
  63. GRB050826: Swift/UVOT early upper limits
  64. GRB050824: First 2 hours of power low optical decay?
  65. GRB 050826: Swift XRT position
  66. GRB050826: Swift-BAT detection of a long burst
  67. GRB050824: MASTER final analysis of the OT observations
  68. Possible GRB050825:MASTER optical observations
  69. Swift-BAT trigger 152038 is definitely not a GRB
  70. GRB050824: CORRECTION to UVOT observing times
  71. Swift-BAT trigger 152038 is probably not a GRB
  72. GRB050824: Swift/UVOT detection of fading afterglow
  73. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  74. GRB050824, I-band imaging
  75. GRB 050822: refined XRT analysis
  76. GRB 050824: XRT refined analysis and possible afterglow detection
  77. GRB 050824: BAT refined analysis of a soft weak burst
  78. GRB050824: MASTER:OT decay
  79. GRB050824: MASTER observation OT
  80. GRB050805a: MASTER optical candidat
  81. GRB 050824: ROTSE-III Optical Limits
  82. GRB050824: Swift-BAT detection of a burst
  83. GRB050822: Swift/UVOT upper limits
  84. GRB 050820A BAT observations of second, larger episode of emission
  85. GRB 050822: Swift-BAT refined analysis
  86. GRB 050820a - corrections to GCN 3846
  87. Swift/UVOT UV Photometry of GRB 050820B
  88. GRB 050822: ROTSE-III Prompt Optical Limits
  89. GRB 050822: Swift detection of a long burst
  90. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  91. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  92. GRB050820a BVRcIc field photometry
  93. GRB050820B XMM-Newton observation
  94. GRB 050820a: NIR Observations by WIRO
  95. GRB 050820B: Swift XRT position
  96. GRB050820B: Refined analysis of the Swift-BAT burst
  97. GRB050820B: BAT-Swift detection of a bright GRB
  98. Swift/UVOT photometry of GRB050820
  99. GRB050820: refined XRT analysis
  100. GRB 050820: Early RAPTOR detections

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