Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

27039 results found.

  1. GRB 051109: Swift-BAT refined analysis
  2. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  3. GRB051109: Swift detection of a burst
  4. GRB 051109a: IR Detections
  5. GRB 051109: ROTSE-III Detection of Possible Counterpart
  6. GRB051105B: Swift/XRT upper limit
  7. GRB051105B: Swift/UVOT upper limit
  8. GRB051103: optical observations
  9. GRB051028: Swift-XRT refined analysis
  10. GRB051105A: Swift/UVOT Observations
  11. XRT observations of GRB 051105A
  12. GRB 051105b: ART optical limits
  13. GRB 051105B (INTEGRAL 2701): Optical observation
  14. GRB 051105: Swift-BAT refined analysis
  15. GRB 051105: Swift detection of a short burst
  16. Konus-Wind observation of GRB 051028
  17. GRB051028 SARA Observation
  18. GRB051028: optical observations
  19. GRB051028: Swift/UVOT upper limits
  20. GRB051028: WHT optical candidate
  21. GRB051028: Swift XRT Position
  22. GRB051021B: Swift/UVOT Upper limits
  23. GRB 051021, Optical Observations
  24. GRB051012: Swift-XRT analysis
  25. GRB051021B: Swift XRT refined analysis
  26. GRB 051022, mm counterpart
  27. GRB 051022: Swift/UVOT Upper Limits
  28. Konus-Wind observation of GRB 051022
  29. GRB051022: Swift XRT Position
  30. GRB 051022 (=H3950): SXC Flight Localization is Valid
  31. GRB051021: Swift/UVOT Upper Limits
  32. GRB 051021B: Refined analysis of the Swift-BAT burst
  33. GRB051022,optical observation
  34. GRB 051022A: ROTSE-III Optical Limits
  35. GRB 051022: Optical observations
  36. GRB 051021,optical observation
  37. GRB051021B: Swift XRT Position
  38. GRB 051021B: Swift detection of a burst
  39. GRB051021: Swift XRT analysis
  40. GRB051021 (=H3947): Refined Analysis
  41. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  42. Swift-BAT trigger 160640 is not a real GRB
  43. GRB051021: A GRB Localized by HETE
  44. Swift-BAT trigger 160619 is not a GRB
  45. Swift-BAT triggered on a posible CR Shower or possible GRB
  46. GRB 051016b: Optical limit
  47. GRB 051016A: Swift/UVOT upper limits
  48. GRB 051016B: Swift/UVOT detection
  49. GRB 051016B: Refined analysis of the Swift-BAT burst
  50. GRB 051016B: Swift detection of a soft burst
  51. GRB 051016: Swift-BAT refined analysis
  52. GRB051016: Swift detection of a burst
  53. GRB 051012: Swift-BAT detection of burst yesterday
  54. Swift trigger 159578 is not a burst
  55. Swift-BAT Trigger 159578 is a possible burst
  56. GRB050805A: Rc optical observations
  57. GRB 051006: Swift/UVOT Upper Limits
  58. GRB051008: Swift XRT refined analysis
  59. GRB051008 - Swift UVOT upper limits
  60. Konus-Wind observation of GRB 051008
  61. GRB051008: Final refined analysis of the Swift-BAT burst
  62. GRB051008: Refined analysis of the Swift-BAT burst
  63. GRB 051008: Swift XRT position
  64. GRB 051008: early Swift XRT analysis
  65. GRB 051008: Swift UVOT Candidate
  66. GRB051008: Swift-BAT detection of a bright burst
  67. GRB 051006: XRT refined analysis
  68. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  69. GRB051006: Refined analysis of the Swift-BAT burst
  70. GRB 051006: XRT position
  71. GRB051006: Swift detection of a burst
  72. GRB051001: Swift UVOT Upper Limits
  73. GRB 051001: Swift XRT refined analysis
  74. GRB 051001: I-band limit
  75. GRB 051001: AAT infra-red observations
  76. GRB 051001: Swift-BAT refined analysis
  77. GRB 051001: Swift Detection of a Burst
  78. GRB 051001: ROTSE-III Optical Limits
  79. GRB050922C: UVES/VLT high resolution spectroscopy
  80. GRB050925: Swift/XRT limits
  81. GRB050922C - Swift UVOT preliminary analysis
  82. GRB050925: Swift UVOT upper limits
  83. Refined analysis of the Swift-BAT soft short burst
  84. GRB050925: Faulkes Telescope North R-band limit
  85. GRB050925: Swift-BAT detection of a short burst
  86. GRB050922C: TNG spectroscopic observations
  87. GRB050922B: refined XRT analysis
  88. Konus-Wind observation of GRB 050922C
  89. GRB050922B: Swift UVOT early upper limits.
  90. GRB OT observation
  91. GRB050922C: observation at MonteBoo
  92. GRB 050922B: optical limit
  93. GRB 050922C: Swift XRT refined analysis
  94. HETE Fregate observations of GRB 050922C
  95. GRB 050922C: Swift-BAT refined analysis
  96. GRB 050922B: Swift-BAT refined analysis
  97. GRB050922C: optical observations
  98. GRB 050922C: optical obserations
  99. GRB 050922C: NOT optical observations
  100. GRB 050922C: Swift detection of a bright burst

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov