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"

19594 results found.

  1. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  2. GRB 051006: optical observations at Sierra Nevada
  3. GRB051006: Refined analysis of the Swift-BAT burst
  4. GRB 051006: XRT position
  5. GRB051006: Swift detection of a burst
  6. Swift-BAT triggers 158261 and 158262 Retraction
  7. GRB051001: Swift UVOT Upper Limits
  8. GRB 050925: Second Epoch WSRT Radio Observations
  9. GRB 051001: Swift XRT refined analysis
  10. GRB 051001, optical observations at Mt. John
  11. GRB 051001: I-band limit
  12. GRB 051001: Swift-BAT refined analysis
  13. GRB 051001: Swift Detection of a Burst
  14. GRB 051001: ROTSE-III Optical Limits
  15. GRB050922B: optical limit
  16. GRB050925: Swift/XRT limits
  17. GRB/SGR 050925: IR Observations
  18. GRB050922C - Swift UVOT preliminary analysis
  19. GRB 050925: WSRT Radio Observations
  20. GRB050925: Swift UVOT upper limits
  21. Refined analysis of the Swift-BAT soft short burst
  22. GRB050925: Faulkes Telescope North R-band limit
  23. GRB050925: Swift-BAT detection of a short burst
  24. GRB 050922B: Correction to BAT refined analysis, longer burst
  25. GRB050922B: refined XRT analysis
  26. Konus-Wind observation of GRB 050922C
  27. GRB050922B: Swift UVOT early upper limits.
  28. GRB 050922B: optical limit
  29. GRB 050922C: Swift XRT refined analysis
  30. HETE Fregate observations of GRB 050922C
  31. GRB 050922C: Swift-BAT refined analysis
  32. GRB 050922B: Swift-BAT refined analysis
  33. GRB050922C: optical observations
  34. GRB 050922C: Absorption redshift from the Nordic Optical Telescope
  35. GRB 050922C: optical obserations
  36. GRB 050922C: NOT optical observations
  37. GRB 050922A: Analysis of Swift/XRT TOO observation
  38. GRB 050922C: Swift detection of a bright burst
  39. GRB 050922C: ROTSE-IIId Refined Analysis
  40. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  41. GRB 050922B: ROTSE-III Optical Limits
  42. GRB 050922B,optical observation
  43. GRB050922B: Swift-BAT detection of a weak long burst
  44. GRB050918: Possible Swift/XRT detected afterglow
  45. GRB050820B: analysis of the XMM-Newton observation
  46. GRB050916: Swift/UVOT Upper Limits
  47. GRB 050916: Swift-BAT refined analysis
  48. Swift-BAT trigger 155764 is not a GRB
  49. Swift-BAT trigger 155764 is probably not a GRB
  50. Swift trigger 155764: bad XRT centroid
  51. Swift-BAT trigger 155535 is definitely not a GRB
  52. GRB050916 : Swift-XRT refined analysis
  53. GRB 050916: XRT position
  54. GRB 050915B: Swift-BAT refined analysis
  55. GRB 050915B: Swift/UVOT Upper Limits
  56. GRB050916: Swift-BAT detection of a long weak burst
  57. GRB 050915B: XRT position
  58. GRB050915B: Swift-BAT detection of a long bright burst
  59. GRB050915: Swift/UVOT upper limits
  60. GRB 050915: KAIT optical limit
  61. GRB 050915: IR Observations
  62. GRB 050915: Swift XRT refined analysis
  63. GRB 050915: Swift-BAT refined analysis
  64. GRB050915, optical observations
  65. GRB050915: XRT position
  66. GRB 050915: ROTSE-III optical limits
  67. GRB 050915: Swift detection of a GRB
  68. GRB050911: Upper limit on X-ray afterglow
  69. Swift-BAT trigger 155072 ground analysis
  70. Swift-BAT trigger 155072 is probably not a GRB
  71. GRB050914: XRT position probably due to cosmic ray
  72. Swift is in normal operation
  73. GRB050911: Swift UVOT followup observations
  74. GRB 050911, optical content of Swift/XRT error box
  75. GRB050911: Swift-XRT position
  76. GRB 050911, optical observations
  77. GRB 050911: Swift-BAT refined analysis
  78. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  79. GRB050911: Swift-BAT detection of a long burst
  80. GRB050908: detection of Swift/UVOT optical counterpart
  81. RBO GRB 050908 observations
  82. WIRO observations in I of GRB 050908
  83. GRB 050906: Possible X-ray Counterpart
  84. GRB050908: Swift/UVOT Early upper limits
  85. GRB050908 : Swift-XRT refined analysis
  86. GRB 050908: Swift-BAT refined analysis
  87. GRB 050908: Optical observations
  88. Gemini Spectroscopy of GRB 050908
  89. GRB 050908 : Swift XRT position
  90. GRB 050908: KAIT observations
  91. GRB 050908: P60 Confirmation of Optical Afterglow
  92. GRB 050908: Swift detection of a burst
  93. Swift trigger 154073 is not a GRB
  94. GRB050904: CrAO optical observations
  95. GRB 050904 BAT refined analysis of complete data set
  96. GRB 050906: MARGE Optical Limits
  97. GRB 050906: Swift-BAT refined analysis
  98. GRB 050906: Swift XRT upper limit
  99. GRB050906: P60 Observations
  100. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?

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