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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"

28050 results found.

  1. GRB051006: Refined analysis of the Swift-BAT burst
  2. GRB051006: Swift detection of a burst
  3. GRB 050906, summary of radio observations
  4. GRB051001: Swift UVOT Upper Limits
  5. GRB 050925: Second Epoch WSRT Radio Observations
  6. GRB 051001: I-band limit
  7. GRB 051001: AAT infra-red observations
  8. GRB 051001: Swift-BAT refined analysis
  9. GRB 051001: Swift Detection of a Burst
  10. GRB 050820A: NIR photometry at the TNG
  11. GRB050925: Swift/XRT limits
  12. GRB/SGR 050925: IR Observations
  13. GRB 050922C: break in the lightcurve
  14. GRB050925: Swift UVOT upper limits
  15. Refined analysis of the Swift-BAT soft short burst
  16. GRB050925: Faulkes Telescope North R-band limit
  17. GRB050925: Swift-BAT detection of a short burst
  18. GRB050922C: TNG spectroscopic observations
  19. GRB050922B: refined XRT analysis
  20. GRB050922B: Swift UVOT early upper limits.
  21. GRB050922C: Optical Observations
  22. GRB 050922C: Swift XRT refined analysis
  23. HETE Fregate observations of GRB 050922C
  24. GRB 050922C: Swift-BAT refined analysis
  25. GRB 050922B: Swift-BAT refined analysis
  26. GRB 050922C: optical obserations
  27. GRB 050922C: NOT optical observations
  28. GRB 050922C: Swift detection of a bright burst
  29. GRB 050922B: ROTSE-III Optical Limits
  30. GRB 050922B,optical observation
  31. GRB050922B: Swift-BAT detection of a weak long burst
  32. GRB050820B: analysis of the XMM-Newton observation
  33. GRB050916: Swift/UVOT Upper Limits
  34. GRB 050916: Swift-BAT refined analysis
  35. Swift-BAT trigger 155764 is not a GRB
  36. Swift-BAT trigger 155764 is probably not a GRB
  37. Swift trigger 155764: bad XRT centroid
  38. Swift-BAT trigger 155535 is definitely not a GRB
  39. GRB050916 : Swift-XRT refined analysis
  40. GRB 050915B: Swift-BAT refined analysis
  41. GRB 050915B: Swift/UVOT Upper Limits
  42. GRB 050915a: IR Transient
  43. GRB 050915b, SMARTS optical/IR observations
  44. GRB050915B: Swift-BAT detection of a long bright burst
  45. GRB050915: Swift/UVOT upper limits
  46. GRB 050915: IR Observations
  47. GRB 050915: Swift XRT refined analysis
  48. GRB 050915: Swift-BAT refined analysis
  49. GRB 050915: Swift detection of a GRB
  50. GRB050911: Upper limit on X-ray afterglow
  51. Swift-BAT trigger 155072 ground analysis
  52. Swift-BAT trigger 155072 is probably not a GRB
  53. GRB 050908: DEIMOS spectrum and further analysis
  54. GRB 050911, optical content of Swift/XRT error box
  55. GRB 050911: Swift-BAT refined analysis
  56. GRB 050911: z~0.16 cluster in the field
  57. GRB050911: Swift-BAT detection of a long burst
  58. GRB 050910a: TAROT early optical limits
  59. WIRO observations in I of GRB 050908
  60. GRB 050906: Possible X-ray Counterpart
  61. GRB050908: Swift/UVOT Early upper limits
  62. GRB050908 : Swift-XRT refined analysis
  63. GRB 050908: Swift-BAT refined analysis
  64. GRB 050908: Optical observations
  65. GRB 050908: Optical Observations
  66. GRB 050908: Swift detection of a burst
  67. GRB 050906: Optical observations at the Very Large Telescope
  68. GRB 050904 BAT refined analysis of complete data set
  69. GRB 050904: Subaru Optical Spectroscopy
  70. GRB 050906: MARGE Optical Limits
  71. GRB 050906: Swift-BAT refined analysis
  72. GRB 050906: Swift XRT upper limit
  73. GRB 050906: Radio Observations
  74. GRB 050904: Keck I-band Imaging
  75. GRB050906: P60 Observations
  76. GRB 050904: more VLT NIR observations
  77. GRB 050904: photometric redshift
  78. GRB 050904: Swift/UVOT observations
  79. GRB 050904: NIR object inside the XRT error box
  80. GRB 050904: early Swift XRT analysis results
  81. GRB 050904: SOAR YJ and PROMPT Ic Observations
  82. GRB050904: Optical Observations
  83. GRB050904: P60 Observations
  84. GRB 050904: TAROT optical limits
  85. GRB 050827 : OSN 1.5m optical observations
  86. GRB 050827: P200 NIR Observations
  87. GRB050827: Swift/UVOT upper limits
  88. GRB 050827: Optical Limit
  89. GRB 050827: XRT possible afterglow detection
  90. GRB 050826 : Lulin R band observation
  91. GRB050824: Maidanak optical limits
  92. GRB 050827: Swift-BAT refined analysis
  93. Subaru Observations of GRB050724
  94. GRB 050826: Optical Candidate
  95. GRB 050826: Swift XRT preliminary analysis results
  96. GRB 050826: BAT refined analysis
  97. GRB050826: Swift/UVOT early upper limits
  98. GRB050826: Swift-BAT detection of a long burst
  99. GRB050824: MASTER final analysis of the OT observations
  100. Swift-BAT trigger 152038 is probably not a GRB

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