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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').
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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"

28085 results found.

  1. GRB 051021: Optical observations and candidate afterglow
  2. GRB051021.63
  3. GRB051021.6: MASTER optical observation
  4. GRB051021: A GRB Localized by HETE
  5. Swift-BAT triggered on a posible CR Shower or possible GRB
  6. GRB 051016b: Optical limit
  7. Afterglow candidate of GRB 051016B observed at Lulin
  8. GRB 051016A: Swift/UVOT upper limits
  9. GRB 051016B: refined analysis of the Swift/XRT data
  10. GRB 051016B: Swift/UVOT detection
  11. GRB 051016B,optical observation
  12. GRB 051016B : Optical follow-up at Lulin
  13. GRB 051016B: Refined analysis of the Swift-BAT burst
  14. GRB 051016B: Swift detection of a soft burst
  15. GRB 051016: Swift-BAT refined analysis
  16. GRB051016 XMM-Newton observation
  17. GRB051016: Swift XRT refined analysis.
  18. GRB 051016: PROMPT Observations
  19. GRB051016: Swift detection of a burst
  20. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  21. GRB 051012: Swift-BAT detection of burst yesterday
  22. Swift-BAT Trigger 159578 is a possible burst
  23. GRB 051006: Swift/UVOT Upper Limits
  24. GRB051008: optical candidate
  25. GRB 051008 - a low redshift low-luminosity burst?
  26. GRB051011: bright nebulae near error box
  27. GRB051011: MASTER optical observation
  28. GRB051008: Final refined analysis of the Swift-BAT burst
  29. GRB051008: Radio Observation
  30. GRB 051008, optical observations
  31. GRB 051008: early Swift XRT analysis
  32. GRB 051008: Swift UVOT Candidate
  33. GRB 051006: P60 Observations
  34. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  35. GRB 051006: optical observations at Sierra Nevada
  36. GRB051006: Refined analysis of the Swift-BAT burst
  37. GRB051006: Swift detection of a burst
  38. GRB 050906, summary of radio observations
  39. GRB051001: Swift UVOT Upper Limits
  40. GRB 050925: Second Epoch WSRT Radio Observations
  41. GRB 051001: I-band limit
  42. GRB 051001: AAT infra-red observations
  43. GRB 051001: Swift-BAT refined analysis
  44. GRB 051001: Swift Detection of a Burst
  45. GRB 050820A: NIR photometry at the TNG
  46. GRB050925: Swift/XRT limits
  47. GRB/SGR 050925: IR Observations
  48. GRB 050922C: break in the lightcurve
  49. GRB050925: Swift UVOT upper limits
  50. Refined analysis of the Swift-BAT soft short burst
  51. GRB050925: Faulkes Telescope North R-band limit
  52. GRB050925: Swift-BAT detection of a short burst
  53. GRB050922C: TNG spectroscopic observations
  54. GRB050922B: refined XRT analysis
  55. GRB050922B: Swift UVOT early upper limits.
  56. GRB050922C: Optical Observations
  57. GRB 050922C: Swift XRT refined analysis
  58. HETE Fregate observations of GRB 050922C
  59. GRB 050922C: Swift-BAT refined analysis
  60. GRB 050922B: Swift-BAT refined analysis
  61. GRB 050922C: optical obserations
  62. GRB 050922C: NOT optical observations
  63. GRB 050922C: Swift detection of a bright burst
  64. GRB 050922B: ROTSE-III Optical Limits
  65. GRB 050922B,optical observation
  66. GRB050922B: Swift-BAT detection of a weak long burst
  67. GRB050820B: analysis of the XMM-Newton observation
  68. GRB050916: Swift/UVOT Upper Limits
  69. GRB 050916: Swift-BAT refined analysis
  70. Swift-BAT trigger 155764 is not a GRB
  71. Swift-BAT trigger 155764 is probably not a GRB
  72. Swift trigger 155764: bad XRT centroid
  73. Swift-BAT trigger 155535 is definitely not a GRB
  74. GRB050916 : Swift-XRT refined analysis
  75. GRB 050915B: Swift-BAT refined analysis
  76. GRB 050915B: Swift/UVOT Upper Limits
  77. GRB 050915a: IR Transient
  78. GRB 050915b, SMARTS optical/IR observations
  79. GRB050915B: Swift-BAT detection of a long bright burst
  80. GRB050915: Swift/UVOT upper limits
  81. GRB 050915: IR Observations
  82. GRB 050915: Swift XRT refined analysis
  83. GRB 050915: Swift-BAT refined analysis
  84. GRB 050915: Swift detection of a GRB
  85. GRB050911: Upper limit on X-ray afterglow
  86. Swift-BAT trigger 155072 ground analysis
  87. Swift-BAT trigger 155072 is probably not a GRB
  88. GRB 050908: DEIMOS spectrum and further analysis
  89. GRB 050911, optical content of Swift/XRT error box
  90. GRB 050911: Swift-BAT refined analysis
  91. GRB 050911: z~0.16 cluster in the field
  92. GRB050911: Swift-BAT detection of a long burst
  93. GRB 050910a: TAROT early optical limits
  94. WIRO observations in I of GRB 050908
  95. GRB 050906: Possible X-ray Counterpart
  96. GRB050908: Swift/UVOT Early upper limits
  97. GRB050908 : Swift-XRT refined analysis
  98. GRB 050908: Swift-BAT refined analysis
  99. GRB 050908: Optical observations
  100. GRB 050908: Optical Observations

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