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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"

28068 results found.

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

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