Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

20868 results found.

  1. GRB 050724: SWIFT XRT refined position
  2. RXTE ASM Detection of GRB050724
  3. GRB050724: Radio Observation
  4. GRB 050724: Optical limit
  5. GRB 050724: Swift/UVOT Upper Limit
  6. GRB050724: Refined analysis of the Swift-BAT possible short burst
  7. GRB 050724: possible host galaxy in DSS
  8. GRB050724: a short-burst detected by Swift
  9. GRB 050721A: Swift-BAT refined analysis
  10. GRB050721A: optical decay
  11. GRB 050721: optical afterglow confirmed
  12. GRB050721A: Swift-BAT detection of a weak burst
  13. GRB 050717: PROMPT RcIc Observations
  14. GRB050714b: Radio Observation
  15. GRB050712: Radio Observations
  16. GRB050713a: Radio Observation
  17. Swift-BAT trigger 146731 is not a real GRB
  18. GRB 050712, Tautenburg optical afterglow observations
  19. Swift-BAT detection of a possible GRB
  20. GRB 050714B: VLT R-band observations
  21. GRB 050717: Additional LCO observations
  22. GRB 050716; J-band observations
  23. GRB 050717: LCO near-IR observations
  24. Swift/UVOT Observations of GRB 050717
  25. GRB 050717: Swift-BAT refined analysis
  26. GRB050717: Swift XRT position
  27. Swift detection of GRB 050717
  28. Swift UVOT Observations of GRB 050716
  29. GRB050716: Refined analysis of the Swift-BAT burst
  30. GRB 050716: Lulin B and R band optical observations
  31. GRB050716, optical observation
  32. GRB 050716: Optical Observations
  33. GRB050716: Faulkes North Telescope observation
  34. GRB050715: Refined analysis of the Swift-BAT burst
  35. GRB 050715: Swift-BAT detection
  36. GRB 050713b: RTT150 optical observations
  37. GRB 050714B: optical afterglow
  38. Swift detection of a long transient (GRB 050714B?)
  39. GRB 050714, R-band candidate
  40. GRB 050714, optical observations
  41. GRB 050714A: ROTSE-III Optical Limits
  42. GRB 050713A: XRT refined analysis
  43. GRB 050709: Spectroscopy
  44. GRB 050713A: RAPTOR detection of early optical emission
  45. GRB050713B :Swift/UVOT observations
  46. GRB050712: TNG R-band observations
  47. GRB 050713B: Swift-BAT Refined Analysis
  48. GRB 050713A: Swift/UVOT observation
  49. GRB 050713A : Swift-BAT Refined Analysis
  50. GRB050712: Swift UVOT Observation of Afterglow Emission
  51. GRB 050713A XMM-Newton observation
  52. GRB050713B: Faulkes North Telescope observation
  53. GRB 050713B
  54. GRB050709 : Chandra source optical counterpart
  55. GRB050713: Liverpool Telescope prompt observations
  56. GRB 050712, optical observations
  57. GRB050709: Candidate X-ray Afterglow from Chandra
  58. GRB050713: possible I-band afterglow
  59. GRB 050713: Swift detection of Bright Burst
  60. GRB 050713A: ROTSE-III Optical Limits
  61. GRB050709: Radio Observations
  62. GRB 050709: Swift UVOT and XRT observations
  63. GRB 050712: Swift-BAT Refined Analysis
  64. GRB050712: UVOT candidate optical counterpart
  65. GRB 050712: Swift detection of a weak burst
  66. GRB 050709: LCO40 Observations
  67. PROMPT Rc Observations of GRB 050709
  68. GRB 050525a: PROMPT VRcIc Detections
  69. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  70. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  71. GRB 050626: Swift XRT observations
  72. GRB 050408: ARC 3.5-meter NIR Observations
  73. Swift UVOT observations of GRB 050701
  74. Swift trigger 143708 is really GRB 050701
  75. GRB 050607, radio observations
  76. GRB050525a: HST Observations
  77. XRF 050509c: Optical monitoring
  78. XRF050509c: Radio Detection
  79. GRB 050607 optical decay
  80. GRB050607: refined analysis of prompt REM observations
  81. Swift/UVOT observations of GRB050607
  82. GRB 050607: PROMPT VRcIc Observations
  83. GRB 050607: Optical decay and spectral slope
  84. GRB050607,optical observation
  85. GRB 050607 - XRT refined data analysis
  86. Optical Afterglow of GRB 050607
  87. GRB050607: Swift Detection of a long GRB
  88. GRB050607: prompt REM observations
  89. GRB 050603: prediction of t_break
  90. Limits on a SN in the field of GRB 050509b
  91. Konus-Wind observation of GRB 050603
  92. GRB050603: Fading Afterglow observed by Swift UVOT
  93. GRB050603, submillimetre observations
  94. GRB050603: Radio Detection
  95. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  96. GRB 050603: INTEGRAL shows it is not a short GRB
  97. Swift/BAT Detection of GRB050603
  98. GRB 050525a, infrared observations
  99. GRB050528, XRT observations
  100. GRB050528: updated Liverpool Telescope limits

Advanced

Download all Circulars as a .tar.gz archive:
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