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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"

28063 results found.

  1. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  2. GRB 050922B: ROTSE-III Optical Limits
  3. GRB050922B: Swift-BAT detection of a weak long burst
  4. GRB050918: Possible Swift/XRT detected afterglow
  5. GRB050820B: analysis of the XMM-Newton observation
  6. GRB050916: Swift/UVOT Upper Limits
  7. GRB 050916: Swift-BAT refined analysis
  8. GRB 050915a: Radio Observations
  9. Swift-BAT trigger 155764 is not a GRB
  10. Swift-BAT trigger 155764 is probably not a GRB
  11. Swift trigger 155764: bad XRT centroid
  12. Swift-BAT trigger 155535 is definitely not a GRB
  13. GRB050916 : Swift-XRT refined analysis
  14. GRB 050916: XRT position
  15. GRB 050915b, SMARTS optical/IR observations of the XRT position
  16. GRB 050915B: Swift-BAT refined analysis
  17. GRB 050915B: Swift/UVOT Upper Limits
  18. GRB050916: Swift-BAT detection of a long weak burst
  19. GRB 050915a: IR Transient
  20. GRB 050915B: XRT position
  21. GRB050915B: Swift-BAT detection of a long bright burst
  22. GRB050915: Swift/UVOT upper limits
  23. GRB 050915: KAIT optical limit
  24. GRB 050915: IR Observations
  25. GRB 050915: Swift XRT refined analysis
  26. GRB 050915: Swift-BAT refined analysis
  27. GRB050915: P60 Optical Observations
  28. GRB050915: XRT position
  29. GRB 050915: Swift detection of a GRB
  30. GRB050911: Upper limit on X-ray afterglow
  31. Swift-BAT trigger 155072 ground analysis
  32. Swift-BAT trigger 155072 is probably not a GRB
  33. GRB050914: XRT position probably due to cosmic ray
  34. GRB 050911: LCO limits on a variable source
  35. GRB 050908: DEIMOS spectrum and further analysis
  36. GRB050911: Swift UVOT followup observations
  37. GRB 050911, optical content of Swift/XRT error box
  38. GRB050911: Swift-XRT position
  39. GRB050911: Swift-BAT detection of a long burst
  40. GRB050908: detection of Swift/UVOT optical counterpart
  41. GRB 050910a: TAROT early optical limits
  42. RBO GRB 050908 observations
  43. GRB 050906: Possible X-ray Counterpart
  44. GRB050908: Swift/UVOT Early upper limits
  45. GRB050908: VLT R-band decay index.
  46. GRB050908 : Swift-XRT refined analysis
  47. GRB 050908: Optical observations
  48. GRB 050908: spectroscopic redshift
  49. GRB 050908: Prompt PROMPT Observations
  50. GRB 050908 : Swift XRT position
  51. GRB 050908: P60 Confirmation of Optical Afterglow
  52. GRB 050908: Swift detection of a burst
  53. Swift trigger 154073 is not a GRB
  54. GRB050904: CrAO optical observations
  55. GRB 050904: Subaru Optical Spectroscopy
  56. GRB 050906: Swift XRT upper limit
  57. GRB 050904: Keck I-band Imaging
  58. GRB 050904: more VLT NIR observations
  59. GRB 050904: BOOTES early R-band observation
  60. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  61. GRB 050906: Bright galaxy in BAT error box
  62. GRB 050906: Swift/BAT Detection of a possible burst
  63. GRB 050904: More SOAR
  64. GRB 050904: photometric redshift
  65. GRB 050904: Swift/UVOT observations
  66. GRB 050904: Afterglow Astrometry
  67. GRB 050904: NIR object inside the XRT error box
  68. GRB 050904: early Swift XRT analysis results
  69. GRB 050904: SOAR YJ and PROMPT Ic Observations
  70. GRB 050904: BAT refined analysis of partial data set
  71. GRB050904: Optical Observations
  72. GRB 050904: Environmental Constraints
  73. GRB 050904: Possible High-Redshift GRB
  74. GRB 050904: SOAR/PROMPT Observations
  75. GRB050904: P60 Observations
  76. GRB050904: Swift-BAT detection of a probable burst
  77. GRB 050824: MDM Observations
  78. GRB 050827: Swift XRT preliminary analysis results
  79. GRB 050827 : OSN 1.5m optical observations
  80. GRB 050827: P200 NIR Observations
  81. GRB050827: Swift/UVOT upper limits
  82. GRB 050827: Optical Limit
  83. GRB 050827: XRT possible afterglow detection
  84. GRB 050826 : Lulin R band observation
  85. GRB050827: Swift-BAT detection of a burst
  86. GRB 050826: Optical Candidate
  87. GRB 050826: Swift XRT preliminary analysis results
  88. GRB 050826: BAT refined analysis
  89. GRB050826: Swift/UVOT early upper limits
  90. GRB 050826: Swift XRT position
  91. GRB050826: Swift-BAT detection of a long burst
  92. GRB050824: MASTER final analysis of the OT observations
  93. Possible GRB050825:MASTER optical observations
  94. GRB050824: CORRECTION to UVOT observing times
  95. Swift-BAT trigger 152038 is probably not a GRB
  96. GRB050824: Swift/UVOT detection of fading afterglow
  97. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  98. GRB050824, I-band imaging
  99. GRB050824: Radio Observations
  100. GRB 050824: Spectroscopic redshift from the VLT

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