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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"

28081 results found.

  1. Swift-BAT triggered on a posible CR Shower or possible GRB
  2. GRB 051016b: Optical limit
  3. Afterglow candidate of GRB 051016B observed at Lulin
  4. GRB 051016A: Swift/UVOT upper limits
  5. GRB 051016B: refined analysis of the Swift/XRT data
  6. GRB 051016B: Swift/UVOT detection
  7. GRB 051016B,optical observation
  8. GRB 051016B : Optical follow-up at Lulin
  9. GRB 051016B: Refined analysis of the Swift-BAT burst
  10. GRB 051016B: Swift detection of a soft burst
  11. GRB 051016: Swift-BAT refined analysis
  12. GRB051016 XMM-Newton observation
  13. GRB051016: Swift XRT refined analysis.
  14. GRB 051016: PROMPT Observations
  15. GRB051016: Swift detection of a burst
  16. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  17. GRB 051012: Swift-BAT detection of burst yesterday
  18. Swift-BAT Trigger 159578 is a possible burst
  19. GRB 051006: Swift/UVOT Upper Limits
  20. GRB051008: optical candidate
  21. GRB 051008 - a low redshift low-luminosity burst?
  22. GRB051011: bright nebulae near error box
  23. GRB051011: MASTER optical observation
  24. GRB051008: Final refined analysis of the Swift-BAT burst
  25. GRB051008: Radio Observation
  26. GRB 051008, optical observations
  27. GRB 051008: early Swift XRT analysis
  28. GRB 051008: Swift UVOT Candidate
  29. GRB 051006: P60 Observations
  30. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  31. GRB 051006: optical observations at Sierra Nevada
  32. GRB051006: Refined analysis of the Swift-BAT burst
  33. GRB051006: Swift detection of a burst
  34. GRB 050906, summary of radio observations
  35. GRB051001: Swift UVOT Upper Limits
  36. GRB 050925: Second Epoch WSRT Radio Observations
  37. GRB 051001: I-band limit
  38. GRB 051001: AAT infra-red observations
  39. GRB 051001: Swift-BAT refined analysis
  40. GRB 051001: Swift Detection of a Burst
  41. GRB 050820A: NIR photometry at the TNG
  42. GRB050925: Swift/XRT limits
  43. GRB/SGR 050925: IR Observations
  44. GRB 050922C: break in the lightcurve
  45. GRB050925: Swift UVOT upper limits
  46. Refined analysis of the Swift-BAT soft short burst
  47. GRB050925: Faulkes Telescope North R-band limit
  48. GRB050925: Swift-BAT detection of a short burst
  49. GRB050922C: TNG spectroscopic observations
  50. GRB050922B: refined XRT analysis
  51. GRB050922B: Swift UVOT early upper limits.
  52. GRB050922C: Optical Observations
  53. GRB 050922C: Swift XRT refined analysis
  54. HETE Fregate observations of GRB 050922C
  55. GRB 050922C: Swift-BAT refined analysis
  56. GRB 050922B: Swift-BAT refined analysis
  57. GRB 050922C: optical obserations
  58. GRB 050922C: NOT optical observations
  59. GRB 050922C: Swift detection of a bright burst
  60. GRB 050922B: ROTSE-III Optical Limits
  61. GRB 050922B,optical observation
  62. GRB050922B: Swift-BAT detection of a weak long burst
  63. GRB050820B: analysis of the XMM-Newton observation
  64. GRB050916: Swift/UVOT Upper Limits
  65. GRB 050916: Swift-BAT refined analysis
  66. Swift-BAT trigger 155764 is not a GRB
  67. Swift-BAT trigger 155764 is probably not a GRB
  68. Swift trigger 155764: bad XRT centroid
  69. Swift-BAT trigger 155535 is definitely not a GRB
  70. GRB050916 : Swift-XRT refined analysis
  71. GRB 050915B: Swift-BAT refined analysis
  72. GRB 050915B: Swift/UVOT Upper Limits
  73. GRB 050915a: IR Transient
  74. GRB 050915b, SMARTS optical/IR observations
  75. GRB050915B: Swift-BAT detection of a long bright burst
  76. GRB050915: Swift/UVOT upper limits
  77. GRB 050915: IR Observations
  78. GRB 050915: Swift XRT refined analysis
  79. GRB 050915: Swift-BAT refined analysis
  80. GRB 050915: Swift detection of a GRB
  81. GRB050911: Upper limit on X-ray afterglow
  82. Swift-BAT trigger 155072 ground analysis
  83. Swift-BAT trigger 155072 is probably not a GRB
  84. GRB 050908: DEIMOS spectrum and further analysis
  85. GRB 050911, optical content of Swift/XRT error box
  86. GRB 050911: Swift-BAT refined analysis
  87. GRB 050911: z~0.16 cluster in the field
  88. GRB050911: Swift-BAT detection of a long burst
  89. GRB 050910a: TAROT early optical limits
  90. WIRO observations in I of GRB 050908
  91. GRB 050906: Possible X-ray Counterpart
  92. GRB050908: Swift/UVOT Early upper limits
  93. GRB050908 : Swift-XRT refined analysis
  94. GRB 050908: Swift-BAT refined analysis
  95. GRB 050908: Optical observations
  96. GRB 050908: Optical Observations
  97. GRB 050908: Swift detection of a burst
  98. GRB 050906: Optical observations at the Very Large Telescope
  99. GRB 050904 BAT refined analysis of complete data set
  100. GRB 050904: Subaru Optical Spectroscopy

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