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"

27394 results found.

  1. Konus-Wind observation of GRB 051028
  2. GRB051028 SARA Observation
  3. GRB051028: optical observations
  4. GRB051028: Swift/UVOT upper limits
  5. GRB051028: WHT optical candidate
  6. GRB051028: Swift XRT Position
  7. GRB051021B: Swift/UVOT Upper limits
  8. GRB 051021, Optical Observations
  9. GRB051012: Swift-XRT analysis
  10. GRB051021B: Swift XRT refined analysis
  11. GRB 051022: Swift/UVOT Upper Limits
  12. Konus-Wind observation of GRB 051022
  13. GRB051022: Swift XRT Position
  14. GRB 051022 (=H3950): SXC Flight Localization is Valid
  15. GRB051021: Swift/UVOT Upper Limits
  16. GRB 051021B: Refined analysis of the Swift-BAT burst
  17. GRB051022,optical observation
  18. GRB 051022A: ROTSE-III Optical Limits
  19. GRB 051022: Optical observations
  20. GRB 051021,optical observation
  21. GRB051021B: Swift XRT Position
  22. GRB 051021B: Swift detection of a burst
  23. GRB051021: Swift XRT analysis
  24. GRB051021 (=H3947): Refined Analysis
  25. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  26. Swift-BAT trigger 160640 is not a real GRB
  27. GRB051021: A GRB Localized by HETE
  28. Swift-BAT trigger 160619 is not a GRB
  29. Swift-BAT triggered on a posible CR Shower or possible GRB
  30. GRB 051016b: Optical limit
  31. GRB 051016A: Swift/UVOT upper limits
  32. GRB 051016B: Swift/UVOT detection
  33. GRB 051016B: Refined analysis of the Swift-BAT burst
  34. GRB 051016B: Swift detection of a soft burst
  35. GRB 051016: Swift-BAT refined analysis
  36. GRB051016: Swift detection of a burst
  37. GRB 051012: Swift-BAT detection of burst yesterday
  38. Swift trigger 159578 is not a burst
  39. Swift-BAT Trigger 159578 is a possible burst
  40. GRB050805A: Rc optical observations
  41. GRB 051006: Swift/UVOT Upper Limits
  42. GRB051008: Swift XRT refined analysis
  43. GRB051008 - Swift UVOT upper limits
  44. Konus-Wind observation of GRB 051008
  45. GRB051008: Final refined analysis of the Swift-BAT burst
  46. GRB051008: Refined analysis of the Swift-BAT burst
  47. GRB051008: Radio Observation
  48. GRB 051008: Swift XRT position
  49. GRB 051008: early Swift XRT analysis
  50. GRB 051008: Swift UVOT Candidate
  51. GRB051008: Swift-BAT detection of a bright burst
  52. GRB 051006: XRT refined analysis
  53. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  54. GRB 051006: optical observations at Sierra Nevada
  55. GRB051006: Refined analysis of the Swift-BAT burst
  56. GRB 051006: XRT position
  57. GRB051006: Swift detection of a burst
  58. GRB 050906, summary of radio observations
  59. Swift-BAT triggers 158261 and 158262 Retraction
  60. GRB051001: Swift UVOT Upper Limits
  61. GRB 050925: Second Epoch WSRT Radio Observations
  62. GRB 051001: Swift XRT refined analysis
  63. GRB 051001: I-band limit
  64. GRB 051001: AAT infra-red observations
  65. GRB 051001: Swift-BAT refined analysis
  66. GRB 051001: Swift Detection of a Burst
  67. GRB 051001: ROTSE-III Optical Limits
  68. GRB050922C: UVES/VLT high resolution spectroscopy
  69. GRB050925: Swift/XRT limits
  70. GRB050922C - Swift UVOT preliminary analysis
  71. GRB 050925: WSRT Radio Observations
  72. GRB050925: Swift UVOT upper limits
  73. Refined analysis of the Swift-BAT soft short burst
  74. GRB050925: Faulkes Telescope North R-band limit
  75. GRB050925: Swift-BAT detection of a short burst
  76. GRB 050922B: Correction to BAT refined analysis, longer burst
  77. GRB050922C: TNG spectroscopic observations
  78. GRB050922B: refined XRT analysis
  79. Konus-Wind observation of GRB 050922C
  80. GRB050922B: Swift UVOT early upper limits.
  81. GRB OT observation
  82. GRB050922C: observation at MonteBoo
  83. GRB 050922B: optical limit
  84. GRB 050922C: Swift XRT refined analysis
  85. HETE Fregate observations of GRB 050922C
  86. GRB 050922C: Swift-BAT refined analysis
  87. GRB 050922B: Swift-BAT refined analysis
  88. GRB050922C: optical observations
  89. GRB 050922C: optical obserations
  90. GRB 050922C: NOT optical observations
  91. GRB 050922C: Swift detection of a bright burst
  92. GRB 050922C: ROTSE-IIId Refined Analysis
  93. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  94. GRB 050922B: ROTSE-III Optical Limits
  95. GRB 050922B,optical observation
  96. GRB050922B: Swift-BAT detection of a weak long burst
  97. Possible GRB 050922 detected by INTEGRAL
  98. GRB050916: Swift/UVOT Upper Limits
  99. GRB 050916: Swift-BAT refined analysis
  100. Swift-BAT trigger 155764 is not a GRB

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