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"

21467 results found.

  1. GRB 051105: Swift-BAT improved refined analysis
  2. GRB 051105: Swift-BAT refined analysis
  3. GRB 051105: Swift detection of a short burst
  4. GRB 051022: RTT150 optical observations
  5. GRB051028: Swift/UVOT upper limits
  6. GRB051028: WHT optical candidate
  7. GRB051028: Swift XRT Position
  8. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  9. GRB051022: Swift XRT measurement of jet break
  10. GRB051021B: Swift/UVOT Upper limits
  11. GRB 051022: XRT Refined Spectral and Temporal Analysis
  12. GRB051012: Swift-XRT analysis
  13. GRB051021B: Swift XRT refined analysis
  14. GRB 051022: WSRT Radio Detection
  15. GRB051022: host galaxy redshift
  16. GRB 051022: Swift/UVOT Upper Limits
  17. GRB051022: IR observations
  18. GRB 051022: SOAR JKs Observations
  19. GRB051021A: Swift XRT refined analysis
  20. GRB051022: Optical Observations
  21. GRB 051022: Magellan NIR imaging
  22. GRB051021b: Magellan IR Imaging
  23. GRB 051022, J & K-band observation
  24. GRB051022: Swift XRT Position
  25. GRB051021: Swift/UVOT Upper Limits
  26. GRB 051021B: Refined analysis of the Swift-BAT burst
  27. GRB051021B: Swift XRT Position
  28. GRB 051021B: Swift detection of a burst
  29. GRB051021: Swift XRT analysis
  30. GRB051021.63
  31. Swift-BAT trigger 160640 is not a real GRB
  32. Swift-BAT trigger 160619 is not a GRB
  33. Swift-BAT triggered on a posible CR Shower or possible GRB
  34. GRB 051016b: Gemini Near IR Observations
  35. GRB 051016A: Swift/UVOT upper limits
  36. GRB 051016B: refined analysis of the Swift/XRT data
  37. GRB 051016B: Swift/UVOT detection
  38. GRB 051016B : Optical follow-up at Lulin
  39. GRB 051016B: Refined analysis of the Swift-BAT burst
  40. GRB 051016B: Swift detection of a soft burst
  41. GRB 051016: Swift-BAT refined analysis
  42. GRB051016 XMM-Newton observation
  43. GRB051016: Swift XRT refined analysis.
  44. GRB 051016: LCO optical and near-IR imaging
  45. GRB 051016: PROMPT Observations
  46. GRB051016: Swift detection of a burst
  47. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  48. GRB051006: optical observations
  49. GRB 051012: Swift-BAT detection of burst yesterday
  50. Swift trigger 159578 is not a burst
  51. Swift-BAT Trigger 159578 is a possible burst
  52. GRB050805A: Rc optical observations
  53. GRB 051006: Swift/UVOT Upper Limits
  54. GRB051008: optical candidate
  55. GRB 051008 - a low redshift low-luminosity burst?
  56. GRB051008: optical observation
  57. GRB051008: Swift XRT refined analysis
  58. GRB051008 - Swift UVOT upper limits
  59. Konus-Wind observation of GRB 051008
  60. GRB051008: Final refined analysis of the Swift-BAT burst
  61. GRB 051008: R-band upper limit
  62. GRB051008: Refined analysis of the Swift-BAT burst
  63. GRB051008: Radio Observation
  64. GRB 051008: Swift XRT position
  65. GRB 051008: early Swift XRT analysis
  66. GRB 051008: Swift UVOT Candidate
  67. GRB051008: Swift-BAT detection of a bright burst
  68. GRB 051006: P60 Observations
  69. GRB 051006: XRT refined analysis
  70. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  71. GRB 051006: optical observations at Sierra Nevada
  72. GRB051006: Refined analysis of the Swift-BAT burst
  73. GRB 051006: XRT position
  74. GRB051006: Swift detection of a burst
  75. GRB 050906, summary of radio observations
  76. Swift-BAT triggers 158261 and 158262 Retraction
  77. GRB051001: Swift UVOT Upper Limits
  78. GRB 050925: Second Epoch WSRT Radio Observations
  79. GRB 051001: Swift XRT refined analysis
  80. GRB 051001, optical observations at Mt. John
  81. GRB 051001: I-band limit
  82. GRB 051001: AAT infra-red observations
  83. GRB 051001: Swift-BAT refined analysis
  84. GRB 051001: Swift Detection of a Burst
  85. GRB 051001: ROTSE-III Optical Limits
  86. GRB050922B: optical limit
  87. GRB050925: Swift/XRT limits
  88. GRB/SGR 050925: IR Observations
  89. GRB050922C - Swift UVOT preliminary analysis
  90. GRB 050925: WSRT Radio Observations
  91. GRB050925: Swift UVOT upper limits
  92. Refined analysis of the Swift-BAT soft short burst
  93. GRB050925: Faulkes Telescope North R-band limit
  94. GRB050925: Swift-BAT detection of a short burst
  95. GRB 050922B: Correction to BAT refined analysis, longer burst
  96. GRB050922B: refined XRT analysis
  97. Konus-Wind observation of GRB 050922C
  98. GRB050922B: Swift UVOT early upper limits.
  99. INT 2.5m limit for GRB050922B
  100. GRB 050922B: optical limit

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