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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"

28051 results found.

  1. GRB 051006: optical observations at Sierra Nevada
  2. GRB051006: Refined analysis of the Swift-BAT burst
  3. GRB051006: Swift detection of a burst
  4. GRB 050906, summary of radio observations
  5. GRB051001: Swift UVOT Upper Limits
  6. GRB 050925: Second Epoch WSRT Radio Observations
  7. GRB 051001: I-band limit
  8. GRB 051001: AAT infra-red observations
  9. GRB 051001: Swift-BAT refined analysis
  10. GRB 051001: Swift Detection of a Burst
  11. GRB 050820A: NIR photometry at the TNG
  12. GRB050925: Swift/XRT limits
  13. GRB/SGR 050925: IR Observations
  14. GRB 050922C: break in the lightcurve
  15. GRB050925: Swift UVOT upper limits
  16. Refined analysis of the Swift-BAT soft short burst
  17. GRB050925: Faulkes Telescope North R-band limit
  18. GRB050925: Swift-BAT detection of a short burst
  19. GRB050922C: TNG spectroscopic observations
  20. GRB050922B: refined XRT analysis
  21. GRB050922B: Swift UVOT early upper limits.
  22. GRB050922C: Optical Observations
  23. GRB 050922C: Swift XRT refined analysis
  24. HETE Fregate observations of GRB 050922C
  25. GRB 050922C: Swift-BAT refined analysis
  26. GRB 050922B: Swift-BAT refined analysis
  27. GRB 050922C: optical obserations
  28. GRB 050922C: NOT optical observations
  29. GRB 050922C: Swift detection of a bright burst
  30. GRB 050922B: ROTSE-III Optical Limits
  31. GRB 050922B,optical observation
  32. GRB050922B: Swift-BAT detection of a weak long burst
  33. GRB050820B: analysis of the XMM-Newton observation
  34. GRB050916: Swift/UVOT Upper Limits
  35. GRB 050916: Swift-BAT refined analysis
  36. Swift-BAT trigger 155764 is not a GRB
  37. Swift-BAT trigger 155764 is probably not a GRB
  38. Swift trigger 155764: bad XRT centroid
  39. Swift-BAT trigger 155535 is definitely not a GRB
  40. GRB050916 : Swift-XRT refined analysis
  41. GRB 050915B: Swift-BAT refined analysis
  42. GRB 050915B: Swift/UVOT Upper Limits
  43. GRB 050915a: IR Transient
  44. GRB 050915b, SMARTS optical/IR observations
  45. GRB050915B: Swift-BAT detection of a long bright burst
  46. GRB050915: Swift/UVOT upper limits
  47. GRB 050915: IR Observations
  48. GRB 050915: Swift XRT refined analysis
  49. GRB 050915: Swift-BAT refined analysis
  50. GRB 050915: Swift detection of a GRB
  51. GRB050911: Upper limit on X-ray afterglow
  52. Swift-BAT trigger 155072 ground analysis
  53. Swift-BAT trigger 155072 is probably not a GRB
  54. GRB 050908: DEIMOS spectrum and further analysis
  55. GRB 050911, optical content of Swift/XRT error box
  56. GRB 050911: Swift-BAT refined analysis
  57. GRB 050911: z~0.16 cluster in the field
  58. GRB050911: Swift-BAT detection of a long burst
  59. GRB 050910a: TAROT early optical limits
  60. WIRO observations in I of GRB 050908
  61. GRB 050906: Possible X-ray Counterpart
  62. GRB050908: Swift/UVOT Early upper limits
  63. GRB050908 : Swift-XRT refined analysis
  64. GRB 050908: Swift-BAT refined analysis
  65. GRB 050908: Optical observations
  66. GRB 050908: Optical Observations
  67. GRB 050908: Swift detection of a burst
  68. GRB 050906: Optical observations at the Very Large Telescope
  69. GRB 050904 BAT refined analysis of complete data set
  70. GRB 050904: Subaru Optical Spectroscopy
  71. GRB 050906: MARGE Optical Limits
  72. GRB 050906: Swift-BAT refined analysis
  73. GRB 050906: Swift XRT upper limit
  74. GRB 050906: Radio Observations
  75. GRB 050904: Keck I-band Imaging
  76. GRB050906: P60 Observations
  77. GRB 050904: more VLT NIR observations
  78. GRB 050904: photometric redshift
  79. GRB 050904: Swift/UVOT observations
  80. GRB 050904: NIR object inside the XRT error box
  81. GRB 050904: early Swift XRT analysis results
  82. GRB 050904: SOAR YJ and PROMPT Ic Observations
  83. GRB050904: Optical Observations
  84. GRB050904: P60 Observations
  85. GRB 050904: TAROT optical limits
  86. GRB 050827 : OSN 1.5m optical observations
  87. GRB 050827: P200 NIR Observations
  88. GRB050827: Swift/UVOT upper limits
  89. GRB 050827: Optical Limit
  90. GRB 050827: XRT possible afterglow detection
  91. GRB 050826 : Lulin R band observation
  92. GRB050824: Maidanak optical limits
  93. GRB 050827: Swift-BAT refined analysis
  94. Subaru Observations of GRB050724
  95. GRB 050826: Optical Candidate
  96. GRB 050826: Swift XRT preliminary analysis results
  97. GRB 050826: BAT refined analysis
  98. GRB050826: Swift/UVOT early upper limits
  99. GRB050826: Swift-BAT detection of a long burst
  100. GRB050824: MASTER final analysis of the OT observations

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