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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"

28062 results found.

  1. GRB051008: optical candidate
  2. GRB 051008 - a low redshift low-luminosity burst?
  3. GRB051011: bright nebulae near error box
  4. GRB051011: MASTER optical observation
  5. GRB051008: Final refined analysis of the Swift-BAT burst
  6. GRB051008: Radio Observation
  7. GRB 051008, optical observations
  8. GRB 051008: early Swift XRT analysis
  9. GRB 051008: Swift UVOT Candidate
  10. GRB 051006: P60 Observations
  11. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  12. GRB 051006: optical observations at Sierra Nevada
  13. GRB051006: Refined analysis of the Swift-BAT burst
  14. GRB051006: Swift detection of a burst
  15. GRB 050906, summary of radio observations
  16. GRB051001: Swift UVOT Upper Limits
  17. GRB 050925: Second Epoch WSRT Radio Observations
  18. GRB 051001: I-band limit
  19. GRB 051001: AAT infra-red observations
  20. GRB 051001: Swift-BAT refined analysis
  21. GRB 051001: Swift Detection of a Burst
  22. GRB 050820A: NIR photometry at the TNG
  23. GRB050925: Swift/XRT limits
  24. GRB/SGR 050925: IR Observations
  25. GRB 050922C: break in the lightcurve
  26. GRB050925: Swift UVOT upper limits
  27. Refined analysis of the Swift-BAT soft short burst
  28. GRB050925: Faulkes Telescope North R-band limit
  29. GRB050925: Swift-BAT detection of a short burst
  30. GRB050922C: TNG spectroscopic observations
  31. GRB050922B: refined XRT analysis
  32. GRB050922B: Swift UVOT early upper limits.
  33. GRB050922C: Optical Observations
  34. GRB 050922C: Swift XRT refined analysis
  35. HETE Fregate observations of GRB 050922C
  36. GRB 050922C: Swift-BAT refined analysis
  37. GRB 050922B: Swift-BAT refined analysis
  38. GRB 050922C: optical obserations
  39. GRB 050922C: NOT optical observations
  40. GRB 050922C: Swift detection of a bright burst
  41. GRB 050922B: ROTSE-III Optical Limits
  42. GRB 050922B,optical observation
  43. GRB050922B: Swift-BAT detection of a weak long burst
  44. GRB050820B: analysis of the XMM-Newton observation
  45. GRB050916: Swift/UVOT Upper Limits
  46. GRB 050916: Swift-BAT refined analysis
  47. Swift-BAT trigger 155764 is not a GRB
  48. Swift-BAT trigger 155764 is probably not a GRB
  49. Swift trigger 155764: bad XRT centroid
  50. Swift-BAT trigger 155535 is definitely not a GRB
  51. GRB050916 : Swift-XRT refined analysis
  52. GRB 050915B: Swift-BAT refined analysis
  53. GRB 050915B: Swift/UVOT Upper Limits
  54. GRB 050915a: IR Transient
  55. GRB 050915b, SMARTS optical/IR observations
  56. GRB050915B: Swift-BAT detection of a long bright burst
  57. GRB050915: Swift/UVOT upper limits
  58. GRB 050915: IR Observations
  59. GRB 050915: Swift XRT refined analysis
  60. GRB 050915: Swift-BAT refined analysis
  61. GRB 050915: Swift detection of a GRB
  62. GRB050911: Upper limit on X-ray afterglow
  63. Swift-BAT trigger 155072 ground analysis
  64. Swift-BAT trigger 155072 is probably not a GRB
  65. GRB 050908: DEIMOS spectrum and further analysis
  66. GRB 050911, optical content of Swift/XRT error box
  67. GRB 050911: Swift-BAT refined analysis
  68. GRB 050911: z~0.16 cluster in the field
  69. GRB050911: Swift-BAT detection of a long burst
  70. GRB 050910a: TAROT early optical limits
  71. WIRO observations in I of GRB 050908
  72. GRB 050906: Possible X-ray Counterpart
  73. GRB050908: Swift/UVOT Early upper limits
  74. GRB050908 : Swift-XRT refined analysis
  75. GRB 050908: Swift-BAT refined analysis
  76. GRB 050908: Optical observations
  77. GRB 050908: Optical Observations
  78. GRB 050908: Swift detection of a burst
  79. GRB 050906: Optical observations at the Very Large Telescope
  80. GRB 050904 BAT refined analysis of complete data set
  81. GRB 050904: Subaru Optical Spectroscopy
  82. GRB 050906: MARGE Optical Limits
  83. GRB 050906: Swift-BAT refined analysis
  84. GRB 050906: Swift XRT upper limit
  85. GRB 050906: Radio Observations
  86. GRB 050904: Keck I-band Imaging
  87. GRB050906: P60 Observations
  88. GRB 050904: more VLT NIR observations
  89. GRB 050904: photometric redshift
  90. GRB 050904: Swift/UVOT observations
  91. GRB 050904: NIR object inside the XRT error box
  92. GRB 050904: early Swift XRT analysis results
  93. GRB 050904: SOAR YJ and PROMPT Ic Observations
  94. GRB050904: Optical Observations
  95. GRB050904: P60 Observations
  96. GRB 050904: TAROT optical limits
  97. GRB 050827 : OSN 1.5m optical observations
  98. GRB 050827: P200 NIR Observations
  99. GRB050827: Swift/UVOT upper limits
  100. GRB 050827: Optical Limit

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