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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"

26364 results found.

  1. Swift-BAT Trigger 159578 is a possible burst
  2. GRB 051006: Swift/UVOT Upper Limits
  3. GRB051008: optical candidate
  4. GRB 051008 - a low redshift low-luminosity burst?
  5. GRB051011: bright nebulae near error box
  6. GRB051011: MASTER optical observation
  7. GRB051008: Final refined analysis of the Swift-BAT burst
  8. GRB051008: Radio Observation
  9. GRB 051008, optical observations
  10. GRB 051008: early Swift XRT analysis
  11. GRB 051008: Swift UVOT Candidate
  12. GRB 051006: P60 Observations
  13. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  14. GRB 051006: optical observations at Sierra Nevada
  15. GRB051006: Refined analysis of the Swift-BAT burst
  16. GRB051006: Swift detection of a burst
  17. GRB 050906, summary of radio observations
  18. GRB051001: Swift UVOT Upper Limits
  19. GRB 050925: Second Epoch WSRT Radio Observations
  20. GRB 051001: I-band limit
  21. GRB 051001: AAT infra-red observations
  22. GRB 051001: Swift-BAT refined analysis
  23. GRB 051001: Swift Detection of a Burst
  24. GRB 050820A: NIR photometry at the TNG
  25. GRB050925: Swift/XRT limits
  26. GRB/SGR 050925: IR Observations
  27. GRB 050922C: break in the lightcurve
  28. GRB050925: Swift UVOT upper limits
  29. Refined analysis of the Swift-BAT soft short burst
  30. GRB050925: Faulkes Telescope North R-band limit
  31. GRB050925: Swift-BAT detection of a short burst
  32. GRB050922C: TNG spectroscopic observations
  33. GRB050922B: refined XRT analysis
  34. GRB050922B: Swift UVOT early upper limits.
  35. GRB050922C: Optical Observations
  36. GRB 050922C: Swift XRT refined analysis
  37. HETE Fregate observations of GRB 050922C
  38. GRB 050922C: Swift-BAT refined analysis
  39. GRB 050922B: Swift-BAT refined analysis
  40. GRB 050922C: optical obserations
  41. GRB 050922C: NOT optical observations
  42. GRB 050922C: Swift detection of a bright burst
  43. GRB 050922B: ROTSE-III Optical Limits
  44. GRB 050922B,optical observation
  45. GRB050922B: Swift-BAT detection of a weak long burst
  46. GRB050820B: analysis of the XMM-Newton observation
  47. GRB050916: Swift/UVOT Upper Limits
  48. GRB 050916: Swift-BAT refined analysis
  49. Swift-BAT trigger 155764 is not a GRB
  50. Swift-BAT trigger 155764 is probably not a GRB
  51. Swift trigger 155764: bad XRT centroid
  52. Swift-BAT trigger 155535 is definitely not a GRB
  53. GRB050916 : Swift-XRT refined analysis
  54. GRB 050915B: Swift-BAT refined analysis
  55. GRB 050915B: Swift/UVOT Upper Limits
  56. GRB 050915a: IR Transient
  57. GRB 050915b, SMARTS optical/IR observations
  58. GRB050915B: Swift-BAT detection of a long bright burst
  59. GRB050915: Swift/UVOT upper limits
  60. GRB 050915: IR Observations
  61. GRB 050915: Swift XRT refined analysis
  62. GRB 050915: Swift-BAT refined analysis
  63. GRB 050915: Swift detection of a GRB
  64. GRB050911: Upper limit on X-ray afterglow
  65. Swift-BAT trigger 155072 ground analysis
  66. Swift-BAT trigger 155072 is probably not a GRB
  67. GRB 050908: DEIMOS spectrum and further analysis
  68. GRB 050911, optical content of Swift/XRT error box
  69. GRB 050911: Swift-BAT refined analysis
  70. GRB 050911: z~0.16 cluster in the field
  71. GRB050911: Swift-BAT detection of a long burst
  72. GRB 050910a: TAROT early optical limits
  73. WIRO observations in I of GRB 050908
  74. GRB 050906: Possible X-ray Counterpart
  75. GRB050908: Swift/UVOT Early upper limits
  76. GRB050908 : Swift-XRT refined analysis
  77. GRB 050908: Swift-BAT refined analysis
  78. GRB 050908: Optical observations
  79. GRB 050908: Optical Observations
  80. GRB 050908: Swift detection of a burst
  81. GRB 050906: Optical observations at the Very Large Telescope
  82. GRB 050904 BAT refined analysis of complete data set
  83. GRB 050904: Subaru Optical Spectroscopy
  84. GRB 050906: MARGE Optical Limits
  85. GRB 050906: Swift-BAT refined analysis
  86. GRB 050906: Swift XRT upper limit
  87. GRB 050906: Radio Observations
  88. GRB 050904: Keck I-band Imaging
  89. GRB050906: P60 Observations
  90. GRB 050904: more VLT NIR observations
  91. GRB 050904: photometric redshift
  92. GRB 050904: Swift/UVOT observations
  93. GRB 050904: NIR object inside the XRT error box
  94. GRB 050904: early Swift XRT analysis results
  95. GRB 050904: SOAR YJ and PROMPT Ic Observations
  96. GRB050904: Optical Observations
  97. GRB050904: P60 Observations
  98. GRB 050904: TAROT optical limits
  99. GRB 050827 : OSN 1.5m optical observations
  100. GRB 050827: P200 NIR Observations

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