Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

24907 results found.

  1. GRB 050721: optical afterglow confirmed
  2. GRB 050709: Refined Spectral and Temporal Properties
  3. GRB050714b: Radio Observation
  4. GRB050712: Radio Observations
  5. GRB050713a: Radio Observation
  6. Swift-BAT trigger 146731 is not a real GRB
  7. GRB 050712, Tautenburg optical afterglow observations
  8. Swift-BAT detection of a possible GRB
  9. GRB 050714B: VLT R-band observations
  10. GRB 050717: Additional LCO observations
  11. GRB 050716; J-band observations
  12. GRB 050717: LCO near-IR observations
  13. Swift/UVOT Observations of GRB 050717
  14. GRB 050717: Swift-BAT refined analysis
  15. GRB 050717: Refined XRT analysis.
  16. GRB050717: Swift XRT position
  17. Swift detection of GRB 050717
  18. Swift UVOT Observations of GRB 050716
  19. GRB 050716: Refined XRT analysis.
  20. GRB050716: Refined analysis of the Swift-BAT burst
  21. GRB 050716: Lulin B and R band optical observations
  22. GRB050716, optical observation
  23. GRB050716: Faulkes North Telescope observation
  24. GRB050715: Refined analysis of the Swift-BAT burst
  25. GRB 050715: Swift-BAT detection
  26. GRB 050714B: refined XRT analysis
  27. GRB 050713b: RTT150 optical observations
  28. GRB050714B: Refined analysis of the Swift-BAT burst
  29. GRB 050714B: optical afterglow
  30. GRB 050714, R-band candidate
  31. GRB 050714, optical observations
  32. GRB 050713A: XRT refined analysis
  33. GRB 050713A: RAPTOR detection of early optical emission
  34. GRB050713B :Swift/UVOT observations
  35. GRB050713b: XRT refined analysis
  36. GRB050712: TNG R-band observations
  37. GRB 050713B: Swift-BAT Refined Analysis
  38. GRB 050713A: Swift/UVOT observation
  39. GRB 050713A : Swift-BAT Refined Analysis
  40. GRB050712: Swift UVOT Observation of Afterglow Emission
  41. GRB 050713A XMM-Newton observation
  42. GRB050713B: Faulkes North Telescope observation
  43. GRB 050713B
  44. GRB050709 : Chandra source optical counterpart
  45. GRB050713: Liverpool Telescope prompt observations
  46. GRB 050712, optical observations
  47. GRB050709: Candidate X-ray Afterglow from Chandra
  48. GRB 050713, R-band observations at NOT
  49. GRB050713: possible I-band afterglow
  50. GRB050709: Radio Observations
  51. GRB 050709: Swift UVOT and XRT observations
  52. GRB 050712: Swift-BAT Refined Analysis
  53. GRB050712: UVOT candidate optical counterpart
  54. GRB 050709: LCO40 Observations
  55. GRB050709, optical observations
  56. GRB050709: A Possible Short-Hard GRB Localized by HETE
  57. PROMPT Rc Observations of GRB 050709
  58. GRB 050525a: PROMPT VRcIc Detections
  59. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  60. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  61. GRB 050626: Swift XRT observations
  62. GRB 050701
  63. GRB 050701, optical observations
  64. GRB 050408: ARC 3.5-meter NIR Observations
  65. GRB 050701: Refined XRT analysis
  66. Swift UVOT observations of GRB 050701
  67. GRB 050607, radio observations
  68. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  69. GRB 050626 - a long GRB detected with INTEGRAL
  70. GRB050525a: HST Observations
  71. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  72. XRF 050509c: Optical monitoring
  73. XRF050509c: Radio Detection
  74. GRB 050416(a): Host Galaxy Redshift Determination
  75. GRB 050607 optical decay
  76. GRB050607: refined analysis of prompt REM observations
  77. GRB 050607: PROMPT VRcIc Observations
  78. GRB 050525a, Mid-Infrared Observations
  79. GRB 050607: Optical decay and spectral slope
  80. GRB 050607: MDM Observations
  81. GRB050607,optical observation
  82. GRB 050607 - XRT refined data analysis
  83. Optical Afterglow of GRB 050607
  84. GRB050607: Swift Detection of a long GRB
  85. GRB050607: prompt REM observations
  86. Limits on a SN in the field of GRB 050509b
  87. GRB 050603: Redshift
  88. GRB050603, submillimetre observations
  89. GRB 050603: Swift XRT Position
  90. GRB050603: Radio Detection
  91. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  92. GRB 050603: INTEGRAL shows it is not a short GRB
  93. GRB 050525a, infrared observations
  94. GRB050528, XRT observations
  95. GRB050528: updated Liverpool Telescope limits
  96. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  97. Possible GRB050528: no candidate from Liverpool Telescope
  98. GRB050525a: Radio Observations
  99. GRB 050509b: refined XRT/Chandra afterglow position analysis
  100. GRB 050525: RTT150, Optical observations

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