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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"

28044 results found.

  1. GRB 051001: AAT infra-red observations
  2. GRB 051001: Swift-BAT refined analysis
  3. GRB 051001: Swift Detection of a Burst
  4. GRB 050820A: NIR photometry at the TNG
  5. GRB050925: Swift/XRT limits
  6. GRB/SGR 050925: IR Observations
  7. GRB 050922C: break in the lightcurve
  8. GRB050925: Swift UVOT upper limits
  9. Refined analysis of the Swift-BAT soft short burst
  10. GRB050925: Faulkes Telescope North R-band limit
  11. GRB050925: Swift-BAT detection of a short burst
  12. GRB050922C: TNG spectroscopic observations
  13. GRB050922B: refined XRT analysis
  14. GRB050922B: Swift UVOT early upper limits.
  15. GRB050922C: Optical Observations
  16. GRB 050922C: Swift XRT refined analysis
  17. HETE Fregate observations of GRB 050922C
  18. GRB 050922C: Swift-BAT refined analysis
  19. GRB 050922B: Swift-BAT refined analysis
  20. GRB 050922C: optical obserations
  21. GRB 050922C: NOT optical observations
  22. GRB 050922C: Swift detection of a bright burst
  23. GRB 050922B: ROTSE-III Optical Limits
  24. GRB 050922B,optical observation
  25. GRB050922B: Swift-BAT detection of a weak long burst
  26. GRB050820B: analysis of the XMM-Newton observation
  27. GRB050916: Swift/UVOT Upper Limits
  28. GRB 050916: Swift-BAT refined analysis
  29. Swift-BAT trigger 155764 is not a GRB
  30. Swift-BAT trigger 155764 is probably not a GRB
  31. Swift trigger 155764: bad XRT centroid
  32. Swift-BAT trigger 155535 is definitely not a GRB
  33. GRB050916 : Swift-XRT refined analysis
  34. GRB 050915B: Swift-BAT refined analysis
  35. GRB 050915B: Swift/UVOT Upper Limits
  36. GRB 050915a: IR Transient
  37. GRB 050915b, SMARTS optical/IR observations
  38. GRB050915B: Swift-BAT detection of a long bright burst
  39. GRB050915: Swift/UVOT upper limits
  40. GRB 050915: IR Observations
  41. GRB 050915: Swift XRT refined analysis
  42. GRB 050915: Swift-BAT refined analysis
  43. GRB 050915: Swift detection of a GRB
  44. GRB050911: Upper limit on X-ray afterglow
  45. Swift-BAT trigger 155072 ground analysis
  46. Swift-BAT trigger 155072 is probably not a GRB
  47. GRB 050908: DEIMOS spectrum and further analysis
  48. GRB 050911, optical content of Swift/XRT error box
  49. GRB 050911: Swift-BAT refined analysis
  50. GRB 050911: z~0.16 cluster in the field
  51. GRB050911: Swift-BAT detection of a long burst
  52. GRB 050910a: TAROT early optical limits
  53. WIRO observations in I of GRB 050908
  54. GRB 050906: Possible X-ray Counterpart
  55. GRB050908: Swift/UVOT Early upper limits
  56. GRB050908 : Swift-XRT refined analysis
  57. GRB 050908: Swift-BAT refined analysis
  58. GRB 050908: Optical observations
  59. GRB 050908: Optical Observations
  60. GRB 050908: Swift detection of a burst
  61. GRB 050906: Optical observations at the Very Large Telescope
  62. GRB 050904 BAT refined analysis of complete data set
  63. GRB 050904: Subaru Optical Spectroscopy
  64. GRB 050906: MARGE Optical Limits
  65. GRB 050906: Swift-BAT refined analysis
  66. GRB 050906: Swift XRT upper limit
  67. GRB 050906: Radio Observations
  68. GRB 050904: Keck I-band Imaging
  69. GRB050906: P60 Observations
  70. GRB 050904: more VLT NIR observations
  71. GRB 050904: photometric redshift
  72. GRB 050904: Swift/UVOT observations
  73. GRB 050904: NIR object inside the XRT error box
  74. GRB 050904: early Swift XRT analysis results
  75. GRB 050904: SOAR YJ and PROMPT Ic Observations
  76. GRB050904: Optical Observations
  77. GRB050904: P60 Observations
  78. GRB 050904: TAROT optical limits
  79. GRB 050827 : OSN 1.5m optical observations
  80. GRB 050827: P200 NIR Observations
  81. GRB050827: Swift/UVOT upper limits
  82. GRB 050827: Optical Limit
  83. GRB 050827: XRT possible afterglow detection
  84. GRB 050826 : Lulin R band observation
  85. GRB050824: Maidanak optical limits
  86. GRB 050827: Swift-BAT refined analysis
  87. Subaru Observations of GRB050724
  88. GRB 050826: Optical Candidate
  89. GRB 050826: Swift XRT preliminary analysis results
  90. GRB 050826: BAT refined analysis
  91. GRB050826: Swift/UVOT early upper limits
  92. GRB050826: Swift-BAT detection of a long burst
  93. GRB050824: MASTER final analysis of the OT observations
  94. Swift-BAT trigger 152038 is probably not a GRB
  95. GRB 050824: XRT refined analysis and possible afterglow detection
  96. GRB 050824: BAT refined analysis of a soft weak burst
  97. GRB050824: MASTER:OT decay
  98. GRB050824: MASTER observation OT
  99. GRB050805a: MASTER optical candidat
  100. XRF050509c: Radio upper limits from GMRT

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