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"
  1. GRB 050721A: Early Swift XRT analysis results
  2. GRB050721A: optical decay
  3. GRB 050721: optical afterglow confirmed
  4. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  5. GRB 050721a: Optical Observations
  6. GRB050721A: Swift-BAT detection of a weak burst
  7. GRB 050709: Refined Spectral and Temporal Properties
  8. GRB 050717: PROMPT RcIc Observations
  9. GRB050714b: Radio Observation
  10. GRB050712: Radio Observations
  11. GRB 050714a: Refined XRT analysis and afterglow confirmation
  12. GRB050713a: Radio Observation
  13. Swift-BAT trigger 146731 is not a real GRB
  14. GRB 050712, Tautenburg optical afterglow observations
  15. Swift-BAT detection of a possible GRB
  16. GRB 050714B: VLT R-band observations
  17. GRB 050717: Additional LCO observations
  18. GRB050717
  19. GRB 050716; J-band observations
  20. Konus-Wind observation of GRB 050717
  21. GRB 050717: LCO near-IR observations
  22. Swift/UVOT Observations of GRB 050717
  23. GRB 050717: Swift-BAT refined analysis
  24. GRB 050717: Refined XRT analysis.
  25. GRB050712: optical limits
  26. GRB050717: Swift XRT position
  27. Swift detection of GRB 050717
  28. GRB 050716 - UKIRT identification of candidate afterglow
  29. Swift UVOT Observations of GRB 050716
  30. GRB 050716: Refined XRT analysis.
  31. GRB050716: Refined analysis of the Swift-BAT burst
  32. GRB 050716: Lulin B and R band optical observations
  33. GRB050716, optical observation
  34. GRB 050716: Optical Observations
  35. GRB050716: Faulkes North Telescope observation
  36. GRB050716: Correction to sign in XRT coordinate
  37. Swift/BAT detection of GRB 050716
  38. GRB050715: Refined analysis of the Swift-BAT burst
  39. GRB 050715: Swift-BAT detection
  40. Swift UVOT Observations of GRB 050714B
  41. Konus-Wind observation of GRB 050713A
  42. GRB 050714B: refined XRT analysis
  43. GRB 050713b: RTT150 optical observations
  44. GRB 050714B: candidate afterglow does not fade
  45. GRB050714B: Refined analysis of the Swift-BAT burst
  46. GRB 050714B: optical afterglow
  47. Swift detection of a long transient (GRB 050714B?)
  48. GRB 050709: optical afterglow candidate
  49. GRB 050714, R-band candidate
  50. GRB 050714: Swift XRT afterglow position
  51. GRB 050714, optical observations
  52. GRB 050714A: ROTSE-III Optical Limits
  53. GRB 050714 - A long GRB detected with INTEGRAL
  54. GRB 050713A: XRT refined analysis
  55. GRB 050709: Spectroscopy
  56. GRB 050713A: RAPTOR detection of early optical emission
  57. GRB050713B :Swift/UVOT observations
  58. GRB050713b: XRT refined analysis
  59. GRB050712: TNG R-band observations
  60. GRB 050713B: Swift-BAT Refined Analysis
  61. Swift-BAT Trigger 145729 is not a GRB
  62. GRB 050713A: Swift/UVOT observation
  63. GRB 050713A : Swift-BAT Refined Analysis
  64. GRB050712: Swift UVOT Observation of Afterglow Emission
  65. GRB 050713A : Lulin R-band observation
  66. GRB 050713A XMM-Newton observation
  67. GRB 050713b : Lulin R-band observations
  68. GRB050713B: Faulkes North Telescope observation
  69. RBO RI observations of GRB 050713A
  70. GRB 050713B
  71. GRB050709 : Chandra source optical counterpart
  72. GRB050713: Liverpool Telescope prompt observations
  73. GRB 050712, optical observations
  74. GRB 050713 : Planned XMM-Newton observation
  75. GRB050709: Candidate X-ray Afterglow from Chandra
  76. GRB 050713, R-band observations at NOT
  77. GRB 050713: ARC NIR Detections and Identification of Fading
  78. GRB050713: possible I-band afterglow
  79. GRB 050713: Swift detection of Bright Burst
  80. GRB 050713A: ROTSE-III Optical Limits
  81. GRB050712: XRT refined analysis
  82. GRB050709: Radio Observations
  83. GRB 050709: Swift UVOT and XRT observations
  84. GRB 050712: Swift-BAT Refined Analysis
  85. GRB050712: UVOT candidate optical counterpart
  86. GRB 050712: Swift XRT afterglow position
  87. GRB 050712: Swift detection of a weak burst
  88. GRB 050709: LCO40 Observations
  89. GRB050709, optical observations
  90. GRB050709: A Possible Short-Hard GRB Localized by HETE
  91. PROMPT Rc Observations of GRB 050709
  92. GRB 050525a: PROMPT VRcIc Detections
  93. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  94. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  95. GRB 050626 optical observations
  96. GRB 050626: Swift XRT observations
  97. GRB 050701
  98. GRB 050701, optical observations
  99. GRB 050408: ARC 3.5-meter NIR Observations
  100. GRB 050701: Refined XRT analysis

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