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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"

18541 results found.

  1. GRB 050915B: Swift-BAT refined analysis
  2. GRB 050915B: Swift/UVOT Upper Limits
  3. GRB050916: Swift-BAT detection of a long weak burst
  4. GRB 050915B: XRT position
  5. GRB050915B: Swift-BAT detection of a long bright burst
  6. GRB050915: Swift/UVOT upper limits
  7. GRB 050915: KAIT optical limit
  8. GRB 050915: IR Observations
  9. GRB 050915: Swift XRT refined analysis
  10. GRB 050915: Swift-BAT refined analysis
  11. GRB050915, optical observations
  12. GRB050915: XRT position
  13. GRB 050915: ROTSE-III optical limits
  14. GRB 050915: Swift detection of a GRB
  15. GRB050911: Upper limit on X-ray afterglow
  16. Swift-BAT trigger 155072 ground analysis
  17. Swift-BAT trigger 155072 is probably not a GRB
  18. GRB050914: XRT position probably due to cosmic ray
  19. Swift is in normal operation
  20. GRB050911: Swift UVOT followup observations
  21. GRB 050911, optical content of Swift/XRT error box
  22. GRB050911: Swift-XRT position
  23. GRB 050911, optical observations
  24. GRB 050911: Swift-BAT refined analysis
  25. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  26. GRB050911: Swift-BAT detection of a long burst
  27. GRB050908: detection of Swift/UVOT optical counterpart
  28. RBO GRB 050908 observations
  29. WIRO observations in I of GRB 050908
  30. GRB 050906: Possible X-ray Counterpart
  31. GRB050908: Swift/UVOT Early upper limits
  32. GRB050908 : Swift-XRT refined analysis
  33. GRB 050908: Swift-BAT refined analysis
  34. GRB 050908: Optical observations
  35. Gemini Spectroscopy of GRB 050908
  36. GRB 050908 : Swift XRT position
  37. GRB 050908: KAIT observations
  38. GRB 050908: P60 Confirmation of Optical Afterglow
  39. GRB 050908: Swift detection of a burst
  40. Swift trigger 154073 is not a GRB
  41. GRB050904: CrAO optical observations
  42. GRB 050904 BAT refined analysis of complete data set
  43. GRB 050906: MARGE Optical Limits
  44. GRB 050906: Swift-BAT refined analysis
  45. GRB 050906: Swift XRT upper limit
  46. GRB050906: P60 Observations
  47. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  48. GRB 050906: Bright galaxy in BAT error box
  49. GRB 050906: Swift/BAT Detection of a possible burst
  50. GRB 050904: Swift/UVOT observations
  51. GRB 050904: early Swift XRT analysis results
  52. GRB 050904: BAT refined analysis of partial data set
  53. GRB050904: P60 Observations
  54. GRB 050904: TAROT optical limits
  55. GRB050904: Swift-BAT detection of a probable burst
  56. Swift-BAT triggers 153461-153465 are not GRBs
  57. Retraction of Swift-BAT trigger #153355
  58. GRB 050824: MDM Observations
  59. GRB 050827: Swift XRT preliminary analysis results
  60. Swift Trigger #152652 is not a GRB
  61. GRB050827: Swift/UVOT upper limits
  62. GRB 050827: Optical Limit
  63. GRB 050827: XRT possible afterglow detection
  64. GRB050827: RTT150 optical observations
  65. GRB 050827: Swift-BAT refined analysis
  66. GRB050827: Swift-BAT detection of a burst
  67. GRB 050826: Optical Candidate
  68. GRB050824, HETE-2 Observation
  69. GRB 050826: Swift XRT preliminary analysis results
  70. GRB 050826: BAT refined analysis
  71. GRB050826: Swift/UVOT early upper limits
  72. GRB050824: First 2 hours of power low optical decay?
  73. GRB 050826: Swift XRT position
  74. GRB050826: Swift-BAT detection of a long burst
  75. GRB050824: MASTER final analysis of the OT observations
  76. Possible GRB050825:MASTER optical observations
  77. Swift-BAT trigger 152038 is definitely not a GRB
  78. GRB050824: CORRECTION to UVOT observing times
  79. Swift-BAT trigger 152038 is probably not a GRB
  80. GRB050824: Swift/UVOT detection of fading afterglow
  81. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  82. GRB050824, I-band imaging
  83. GRB 050822: refined XRT analysis
  84. GRB 050824: XRT refined analysis and possible afterglow detection
  85. GRB 050824: BAT refined analysis of a soft weak burst
  86. GRB050824: MASTER:OT decay
  87. GRB050824: MASTER observation OT
  88. GRB050805a: MASTER optical candidat
  89. GRB 050824: ROTSE-III Optical Limits
  90. GRB050824: Swift-BAT detection of a burst
  91. GRB050822: Swift/UVOT upper limits
  92. GRB 050820A BAT observations of second, larger episode of emission
  93. GRB 050822: Swift-BAT refined analysis
  94. GRB 050820a - corrections to GCN 3846
  95. Swift/UVOT UV Photometry of GRB 050820B
  96. GRB 050822: ROTSE-III Prompt Optical Limits
  97. GRB 050822: Swift detection of a long burst
  98. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  99. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  100. GRB050820a BVRcIc field photometry

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