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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"

28047 results found.

  1. GRB051001: Swift UVOT Upper Limits
  2. GRB 050925: Second Epoch WSRT Radio Observations
  3. GRB 051001: I-band limit
  4. GRB 051001: AAT infra-red observations
  5. GRB 051001: Swift-BAT refined analysis
  6. GRB 051001: Swift Detection of a Burst
  7. GRB 050820A: NIR photometry at the TNG
  8. GRB050925: Swift/XRT limits
  9. GRB/SGR 050925: IR Observations
  10. GRB 050922C: break in the lightcurve
  11. GRB050925: Swift UVOT upper limits
  12. Refined analysis of the Swift-BAT soft short burst
  13. GRB050925: Faulkes Telescope North R-band limit
  14. GRB050925: Swift-BAT detection of a short burst
  15. GRB050922C: TNG spectroscopic observations
  16. GRB050922B: refined XRT analysis
  17. GRB050922B: Swift UVOT early upper limits.
  18. GRB050922C: Optical Observations
  19. GRB 050922C: Swift XRT refined analysis
  20. HETE Fregate observations of GRB 050922C
  21. GRB 050922C: Swift-BAT refined analysis
  22. GRB 050922B: Swift-BAT refined analysis
  23. GRB 050922C: optical obserations
  24. GRB 050922C: NOT optical observations
  25. GRB 050922C: Swift detection of a bright burst
  26. GRB 050922B: ROTSE-III Optical Limits
  27. GRB 050922B,optical observation
  28. GRB050922B: Swift-BAT detection of a weak long burst
  29. GRB050820B: analysis of the XMM-Newton observation
  30. GRB050916: Swift/UVOT Upper Limits
  31. GRB 050916: Swift-BAT refined analysis
  32. Swift-BAT trigger 155764 is not a GRB
  33. Swift-BAT trigger 155764 is probably not a GRB
  34. Swift trigger 155764: bad XRT centroid
  35. Swift-BAT trigger 155535 is definitely not a GRB
  36. GRB050916 : Swift-XRT refined analysis
  37. GRB 050915B: Swift-BAT refined analysis
  38. GRB 050915B: Swift/UVOT Upper Limits
  39. GRB 050915a: IR Transient
  40. GRB 050915b, SMARTS optical/IR observations
  41. GRB050915B: Swift-BAT detection of a long bright burst
  42. GRB050915: Swift/UVOT upper limits
  43. GRB 050915: IR Observations
  44. GRB 050915: Swift XRT refined analysis
  45. GRB 050915: Swift-BAT refined analysis
  46. GRB 050915: Swift detection of a GRB
  47. GRB050911: Upper limit on X-ray afterglow
  48. Swift-BAT trigger 155072 ground analysis
  49. Swift-BAT trigger 155072 is probably not a GRB
  50. GRB 050908: DEIMOS spectrum and further analysis
  51. GRB 050911, optical content of Swift/XRT error box
  52. GRB 050911: Swift-BAT refined analysis
  53. GRB 050911: z~0.16 cluster in the field
  54. GRB050911: Swift-BAT detection of a long burst
  55. GRB 050910a: TAROT early optical limits
  56. WIRO observations in I of GRB 050908
  57. GRB 050906: Possible X-ray Counterpart
  58. GRB050908: Swift/UVOT Early upper limits
  59. GRB050908 : Swift-XRT refined analysis
  60. GRB 050908: Swift-BAT refined analysis
  61. GRB 050908: Optical observations
  62. GRB 050908: Optical Observations
  63. GRB 050908: Swift detection of a burst
  64. GRB 050906: Optical observations at the Very Large Telescope
  65. GRB 050904 BAT refined analysis of complete data set
  66. GRB 050904: Subaru Optical Spectroscopy
  67. GRB 050906: MARGE Optical Limits
  68. GRB 050906: Swift-BAT refined analysis
  69. GRB 050906: Swift XRT upper limit
  70. GRB 050906: Radio Observations
  71. GRB 050904: Keck I-band Imaging
  72. GRB050906: P60 Observations
  73. GRB 050904: more VLT NIR observations
  74. GRB 050904: photometric redshift
  75. GRB 050904: Swift/UVOT observations
  76. GRB 050904: NIR object inside the XRT error box
  77. GRB 050904: early Swift XRT analysis results
  78. GRB 050904: SOAR YJ and PROMPT Ic Observations
  79. GRB050904: Optical Observations
  80. GRB050904: P60 Observations
  81. GRB 050904: TAROT optical limits
  82. GRB 050827 : OSN 1.5m optical observations
  83. GRB 050827: P200 NIR Observations
  84. GRB050827: Swift/UVOT upper limits
  85. GRB 050827: Optical Limit
  86. GRB 050827: XRT possible afterglow detection
  87. GRB 050826 : Lulin R band observation
  88. GRB050824: Maidanak optical limits
  89. GRB 050827: Swift-BAT refined analysis
  90. Subaru Observations of GRB050724
  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. GRB050826: Swift-BAT detection of a long burst
  96. GRB050824: MASTER final analysis of the OT observations
  97. Swift-BAT trigger 152038 is probably not a GRB
  98. GRB 050824: XRT refined analysis and possible afterglow detection
  99. GRB 050824: BAT refined analysis of a soft weak burst
  100. GRB050824: MASTER:OT decay

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