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"

16161 results found.

  1. GRB 050727: RTT150 optical observations
  2. GRB050727: KAIT optical limit
  3. GRB050709: Second Epoch Chandra Observation
  4. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  5. GRB050724: Further Radio Observations
  6. GRB050726: Swift-BAT detection of a weak burst
  7. GRB 050724: Optical Variability in Nearby Galaxy
  8. GRB 050724: Optical limit
  9. GRB 050724: optical and near-IR observations
  10. GRB 050724: Optical imaging/astrometry
  11. GRB 050724: RTT150 optical observations
  12. GRB 050724: early Swift XRT analysis results
  13. GRB050721A: optical decay
  14. GRB 050721: optical afterglow confirmed
  15. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  16. GRB 050721a: Optical Observations
  17. GRB 050709: Refined Spectral and Temporal Properties
  18. GRB050712: Radio Observations
  19. GRB050713a: Radio Observation
  20. GRB 050712, Tautenburg optical afterglow observations
  21. Swift-BAT detection of a possible GRB
  22. GRB050712: optical limits
  23. Swift detection of GRB 050717
  24. GRB 050716: Lulin B and R band optical observations
  25. GRB050716, optical observation
  26. GRB 050716: Optical Observations
  27. Swift/BAT detection of GRB 050716
  28. GRB 050713b: RTT150 optical observations
  29. GRB 050714B: candidate afterglow does not fade
  30. GRB 050714B: optical afterglow
  31. Swift detection of a long transient (GRB 050714B?)
  32. GRB 050709: optical afterglow candidate
  33. GRB 050714, optical observations
  34. GRB 050714A: ROTSE-III Optical Limits
  35. GRB 050709: Spectroscopy
  36. GRB 050713A: RAPTOR detection of early optical emission
  37. GRB050712: Swift UVOT Observation of Afterglow Emission
  38. GRB 050713B
  39. GRB050709 : Chandra source optical counterpart
  40. GRB 050712, optical observations
  41. GRB050709: Candidate X-ray Afterglow from Chandra
  42. GRB 050713, R-band observations at NOT
  43. GRB 050713: Swift detection of Bright Burst
  44. GRB 050713A: ROTSE-III Optical Limits
  45. GRB 050709: Swift UVOT and XRT observations
  46. GRB050712: UVOT candidate optical counterpart
  47. GRB 050712: Swift detection of a weak burst
  48. GRB050709, optical observations
  49. GRB050709: A Possible Short-Hard GRB Localized by HETE
  50. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  51. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  52. GRB 050626 optical observations
  53. GRB 050626: Swift XRT observations
  54. GRB 050701, optical observations
  55. GRB 050607, radio observations
  56. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  57. GRB 050525A: Swift Late-Time Decay Rate
  58. H3804: A Possible New XRB Detected by HETE
  59. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  60. XRF 050509c: Optical monitoring
  61. XRF050509c: Radio Detection
  62. GRB 050607 optical decay
  63. GRB 050607: RTT150 optical observations
  64. GRB050607: refined analysis of prompt REM observations
  65. Swift/UVOT observations of GRB050607
  66. GRB 050607: RAPTOR-S Early Optical Limits
  67. GRB050607: KAIT optical limits
  68. GRB 050525a, Mid-Infrared Observations
  69. GRB 050607: Optical decay and spectral slope
  70. GRB 050607: MDM Observations
  71. GRB050607,optical observation
  72. GRB 050607 - XRT refined data analysis
  73. Optical Afterglow of GRB 050607
  74. GRB050607 optical limit by "Pi of the Sky"
  75. GRB050607: prompt REM observations
  76. GRB050603: Fading Afterglow observed by Swift UVOT
  77. GRB 050603: Swift XRT Position
  78. GRB050603: Radio Detection
  79. GRB 050525a, SMARTS optical/IR afterglow observations
  80. GRB050528: BOOTES optical candidate (retraction)
  81. GRB050528: BOOTES optical candidate
  82. GRB050525a: Radio Observations
  83. GRB 050525: RTT150, Optical observations
  84. GRB050525a: optical upper limits
  85. GRB 050525a: SARA Observations
  86. GRB 050525: MITSuME Optical Observation in VRI
  87. GRB 050525a: MDM Observations
  88. GRB050525A,optical observation
  89. GRB 050525 : Lulin optical afterglow observations
  90. GRB050525: Super-LOTIS observations
  91. GRB 050525a: Gemini/GMOS Spectra
  92. GRB050306: optical afterglow not confirmed
  93. GRB 050525: BART optical observation
  94. GRB 050525A: BOOTES simultaneous optical observations
  95. GRB 050525A: Swift-BAT refined analysis
  96. GRB050525: Optical observations
  97. Swift/UVOT UV and optical detections of GRB 050525
  98. GRB 050525, infrared observations
  99. GRB 050525: Optical observation
  100. GRB 050525: observatons of the optical afterglow

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