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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"

28045 results found.

  1. GRB 051001: I-band limit
  2. GRB 051001: AAT infra-red observations
  3. GRB 051001: Swift-BAT refined analysis
  4. GRB 051001: Swift Detection of a Burst
  5. GRB 050820A: NIR photometry at the TNG
  6. GRB050925: Swift/XRT limits
  7. GRB/SGR 050925: IR Observations
  8. GRB 050922C: break in the lightcurve
  9. GRB050925: Swift UVOT upper limits
  10. Refined analysis of the Swift-BAT soft short burst
  11. GRB050925: Faulkes Telescope North R-band limit
  12. GRB050925: Swift-BAT detection of a short burst
  13. GRB050922C: TNG spectroscopic observations
  14. GRB050922B: refined XRT analysis
  15. GRB050922B: Swift UVOT early upper limits.
  16. GRB050922C: Optical Observations
  17. GRB 050922C: Swift XRT refined analysis
  18. HETE Fregate observations of GRB 050922C
  19. GRB 050922C: Swift-BAT refined analysis
  20. GRB 050922B: Swift-BAT refined analysis
  21. GRB 050922C: optical obserations
  22. GRB 050922C: NOT optical observations
  23. GRB 050922C: Swift detection of a bright burst
  24. GRB 050922B: ROTSE-III Optical Limits
  25. GRB 050922B,optical observation
  26. GRB050922B: Swift-BAT detection of a weak long burst
  27. GRB050820B: analysis of the XMM-Newton observation
  28. GRB050916: Swift/UVOT Upper Limits
  29. GRB 050916: Swift-BAT refined analysis
  30. Swift-BAT trigger 155764 is not a GRB
  31. Swift-BAT trigger 155764 is probably not a GRB
  32. Swift trigger 155764: bad XRT centroid
  33. Swift-BAT trigger 155535 is definitely not a GRB
  34. GRB050916 : Swift-XRT refined analysis
  35. GRB 050915B: Swift-BAT refined analysis
  36. GRB 050915B: Swift/UVOT Upper Limits
  37. GRB 050915a: IR Transient
  38. GRB 050915b, SMARTS optical/IR observations
  39. GRB050915B: Swift-BAT detection of a long bright burst
  40. GRB050915: Swift/UVOT upper limits
  41. GRB 050915: IR Observations
  42. GRB 050915: Swift XRT refined analysis
  43. GRB 050915: Swift-BAT refined analysis
  44. GRB 050915: Swift detection of a GRB
  45. GRB050911: Upper limit on X-ray afterglow
  46. Swift-BAT trigger 155072 ground analysis
  47. Swift-BAT trigger 155072 is probably not a GRB
  48. GRB 050908: DEIMOS spectrum and further analysis
  49. GRB 050911, optical content of Swift/XRT error box
  50. GRB 050911: Swift-BAT refined analysis
  51. GRB 050911: z~0.16 cluster in the field
  52. GRB050911: Swift-BAT detection of a long burst
  53. GRB 050910a: TAROT early optical limits
  54. WIRO observations in I of GRB 050908
  55. GRB 050906: Possible X-ray Counterpart
  56. GRB050908: Swift/UVOT Early upper limits
  57. GRB050908 : Swift-XRT refined analysis
  58. GRB 050908: Swift-BAT refined analysis
  59. GRB 050908: Optical observations
  60. GRB 050908: Optical Observations
  61. GRB 050908: Swift detection of a burst
  62. GRB 050906: Optical observations at the Very Large Telescope
  63. GRB 050904 BAT refined analysis of complete data set
  64. GRB 050904: Subaru Optical Spectroscopy
  65. GRB 050906: MARGE Optical Limits
  66. GRB 050906: Swift-BAT refined analysis
  67. GRB 050906: Swift XRT upper limit
  68. GRB 050906: Radio Observations
  69. GRB 050904: Keck I-band Imaging
  70. GRB050906: P60 Observations
  71. GRB 050904: more VLT NIR observations
  72. GRB 050904: photometric redshift
  73. GRB 050904: Swift/UVOT observations
  74. GRB 050904: NIR object inside the XRT error box
  75. GRB 050904: early Swift XRT analysis results
  76. GRB 050904: SOAR YJ and PROMPT Ic Observations
  77. GRB050904: Optical Observations
  78. GRB050904: P60 Observations
  79. GRB 050904: TAROT optical limits
  80. GRB 050827 : OSN 1.5m optical observations
  81. GRB 050827: P200 NIR Observations
  82. GRB050827: Swift/UVOT upper limits
  83. GRB 050827: Optical Limit
  84. GRB 050827: XRT possible afterglow detection
  85. GRB 050826 : Lulin R band observation
  86. GRB050824: Maidanak optical limits
  87. GRB 050827: Swift-BAT refined analysis
  88. Subaru Observations of GRB050724
  89. GRB 050826: Optical Candidate
  90. GRB 050826: Swift XRT preliminary analysis results
  91. GRB 050826: BAT refined analysis
  92. GRB050826: Swift/UVOT early upper limits
  93. GRB050826: Swift-BAT detection of a long burst
  94. GRB050824: MASTER final analysis of the OT observations
  95. Swift-BAT trigger 152038 is probably not a GRB
  96. GRB 050824: XRT refined analysis and possible afterglow detection
  97. GRB 050824: BAT refined analysis of a soft weak burst
  98. GRB050824: MASTER:OT decay
  99. GRB050824: MASTER observation OT
  100. GRB050805a: MASTER optical candidat

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