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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"

25995 results found.

  1. GRB051022: Swift XRT Position
  2. GRB 051021: P200 Ks Observations
  3. GRB 051022 (=H3950): SXC Flight Localization is Valid
  4. GRB051021: Swift/UVOT Upper Limits
  5. GRB 051021B: Refined analysis of the Swift-BAT burst
  6. GRB 051022: SSO40 Optical Observations
  7. GRB051022,optical observation
  8. GRB 051021,optical observation
  9. GRB 051021B: Swift detection of a burst
  10. GRB 051021 : optical afterglow observation at Lulin
  11. GRB 051021: Optical observations and candidate afterglow
  12. GRB051021.63
  13. GRB051021.6: MASTER optical observation
  14. GRB051021: A GRB Localized by HETE
  15. Swift-BAT triggered on a posible CR Shower or possible GRB
  16. GRB 051016b: Optical limit
  17. Afterglow candidate of GRB 051016B observed at Lulin
  18. GRB 051016A: Swift/UVOT upper limits
  19. GRB 051016B: refined analysis of the Swift/XRT data
  20. GRB 051016B: Swift/UVOT detection
  21. GRB 051016B,optical observation
  22. GRB 051016B : Optical follow-up at Lulin
  23. GRB 051016B: Refined analysis of the Swift-BAT burst
  24. GRB 051016B: Swift detection of a soft burst
  25. GRB 051016: Swift-BAT refined analysis
  26. GRB051016 XMM-Newton observation
  27. GRB051016: Swift XRT refined analysis.
  28. GRB 051016: PROMPT Observations
  29. GRB051016: Swift detection of a burst
  30. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  31. GRB 051012: Swift-BAT detection of burst yesterday
  32. Swift-BAT Trigger 159578 is a possible burst
  33. GRB 051006: Swift/UVOT Upper Limits
  34. GRB051008: optical candidate
  35. GRB 051008 - a low redshift low-luminosity burst?
  36. GRB051011: bright nebulae near error box
  37. GRB051011: MASTER optical observation
  38. GRB051008: Final refined analysis of the Swift-BAT burst
  39. GRB051008: Radio Observation
  40. GRB 051008, optical observations
  41. GRB 051008: early Swift XRT analysis
  42. GRB 051008: Swift UVOT Candidate
  43. GRB 051006: P60 Observations
  44. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  45. GRB 051006: optical observations at Sierra Nevada
  46. GRB051006: Refined analysis of the Swift-BAT burst
  47. GRB051006: Swift detection of a burst
  48. GRB 050906, summary of radio observations
  49. GRB051001: Swift UVOT Upper Limits
  50. GRB 050925: Second Epoch WSRT Radio Observations
  51. GRB 051001: I-band limit
  52. GRB 051001: AAT infra-red observations
  53. GRB 051001: Swift-BAT refined analysis
  54. GRB 051001: Swift Detection of a Burst
  55. GRB 050820A: NIR photometry at the TNG
  56. GRB050925: Swift/XRT limits
  57. GRB/SGR 050925: IR Observations
  58. GRB 050922C: break in the lightcurve
  59. GRB050925: Swift UVOT upper limits
  60. Refined analysis of the Swift-BAT soft short burst
  61. GRB050925: Faulkes Telescope North R-band limit
  62. GRB050925: Swift-BAT detection of a short burst
  63. GRB050922C: TNG spectroscopic observations
  64. GRB050922B: refined XRT analysis
  65. GRB050922B: Swift UVOT early upper limits.
  66. GRB050922C: Optical Observations
  67. GRB 050922C: Swift XRT refined analysis
  68. HETE Fregate observations of GRB 050922C
  69. GRB 050922C: Swift-BAT refined analysis
  70. GRB 050922B: Swift-BAT refined analysis
  71. GRB 050922C: optical obserations
  72. GRB 050922C: NOT optical observations
  73. GRB 050922C: Swift detection of a bright burst
  74. GRB 050922B: ROTSE-III Optical Limits
  75. GRB 050922B,optical observation
  76. GRB050922B: Swift-BAT detection of a weak long burst
  77. GRB050820B: analysis of the XMM-Newton observation
  78. GRB050916: Swift/UVOT Upper Limits
  79. GRB 050916: Swift-BAT refined analysis
  80. Swift-BAT trigger 155764 is not a GRB
  81. Swift-BAT trigger 155764 is probably not a GRB
  82. Swift trigger 155764: bad XRT centroid
  83. Swift-BAT trigger 155535 is definitely not a GRB
  84. GRB050916 : Swift-XRT refined analysis
  85. GRB 050915B: Swift-BAT refined analysis
  86. GRB 050915B: Swift/UVOT Upper Limits
  87. GRB 050915a: IR Transient
  88. GRB 050915b, SMARTS optical/IR observations
  89. GRB050915B: Swift-BAT detection of a long bright burst
  90. GRB050915: Swift/UVOT upper limits
  91. GRB 050915: IR Observations
  92. GRB 050915: Swift XRT refined analysis
  93. GRB 050915: Swift-BAT refined analysis
  94. GRB 050915: Swift detection of a GRB
  95. GRB050911: Upper limit on X-ray afterglow
  96. Swift-BAT trigger 155072 ground analysis
  97. Swift-BAT trigger 155072 is probably not a GRB
  98. GRB 050908: DEIMOS spectrum and further analysis
  99. GRB 050911, optical content of Swift/XRT error box
  100. GRB 050911: Swift-BAT refined analysis

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