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"

18791 results found.

  1. GRB 050509a: Swift XRT Position
  2. Swift Detection of the Burst GRB050509
  3. Swift-BAT detection of GRB 050507
  4. GRB 050505: early time observations
  5. GRB 050505 - Faulkes Telescope North observations
  6. GRB 050502a: Swift XRT Upper Limit
  7. GRB 050505, simultaneous optical observation
  8. GRB 050505: Further Swift UVOT observations.
  9. GRB050416A : 1 GHz limit from GMRT
  10. GRB 050505 UVOT
  11. GRB 050505: Swift XRT Position
  12. GRB050505 Swift-BAT refined analysis
  13. GRB 050416b:Swift XRT afterglow upper limits
  14. GRB 050416b:Swift XRT afterglow upper limits
  15. Swift-BAT detection of GRB050505
  16. GRB 050504: Swift XRT position
  17. Swift UVOT observation of GRB 050504
  18. GRB 050502b, V band Observations
  19. GRB050502B Swift-BAT refined analysis
  20. GRB050502B: I band source in XRT error circle
  21. Swift UVOT refined analysis
  22. Retraction of Swift-BAT trigger 116145
  23. GRB 050502b : optical observation at Lulin observatory
  24. GRB 050502b: Swift XRT Position
  25. GRB050502B: Optical Limits from ANU 1m
  26. Swift Detection of the Bright Burst GRB050502b
  27. GRB050502: ANU 1m optical Observations
  28. Swift-BAT Trigger 115881 is not a real GRB
  29. Swift/BAT possible detection of a weak burst GRB050430
  30. GRB 050401: Rc observation
  31. GRB050416a: Radio Detection
  32. GRB 050422: Swift-UVOT observation
  33. GRB 050422: Swift-BAT refined analysis
  34. GRB 050422: Swift XRT Position
  35. Swift Detection of GRB 050422
  36. GRB 050421: SLOTIS observations
  37. GRB050421: Radio Observations
  38. GRB050421: Radio Observations
  39. GRB 050421: Swift-UVOT observation
  40. GRB 050421: Swift-BAT refined analysis
  41. GRB 050421: ROTSE-III Optical Limits
  42. GRB 050421: early Swift XRT analysis results
  43. GRB 050421: BOOTES-2 simultaneous optical observations
  44. GRB 050421: Optical observations at the INT
  45. Swift Detection of GRB050421
  46. GRB 050416b: Tentative Swift XRT Position
  47. GRB050326: analysis of the XMM-Newton observation
  48. GRB 050418: Swift-BAT refined analysis
  49. Swift-BAT detection of the bright and long GRB 050418
  50. GRB 050416B: optical observations
  51. GRB 050416b: Swift-BAT refined analysis
  52. GRB 050416: Swift/UVOT refined analysis
  53. Swift-BAT detection of GRB 050416b
  54. GRB050412: Radio Observations
  55. GRB 050416: Swift/UVOT detection of afterglow emission
  56. GRB050416: Refined Swift-XRT analysis
  57. GRB050416: Maidanak optical observations
  58. GRB 050416: Swift-BAT refined analysis
  59. GRB 050416,optical observation
  60. GRB 050416: KAIT observations
  61. GRB 050416: Swift XRT Position
  62. GRB 050416: Radio observations
  63. Confirmation of OT for GRB050416
  64. GRB050416: P60 Afterglow Candidate
  65. Swift BAT/XRT Detection of GRB 050416
  66. GRB 050412: Subaru observations
  67. GRB 050412: optical limit
  68. GRB 050412: optical observations
  69. GRB 050408: refined XRT analysis, no jet break seen yet
  70. GRB 050412: early Swift XRT analysis results
  71. GRB 050412: Swift-BAT refined analysis
  72. GRB 050412: ANU 2.3m observations
  73. GRB 050412: Early Optical/Ultraviolet Observations with
  74. GRB 050412: retraction of UVOT transient report
  75. GRB 050412: UVOT transient not in XRT error circle
  76. GRB 050412: Swift XRT Position
  77. GRB050412: optical limit before and during GRB
  78. GRB050412: ROTSE-III Optical Limits
  79. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  80. GRB 050412: IR Observations
  81. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  82. GRB 050410, optical observations
  83. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  84. GRB 050410 R band Optical Observations
  85. GRB050410 : Null detection report
  86. GRB 050410, optical observations
  87. GRB050410: Radio Observations
  88. GRB 050408: Swift XRT measurement of possible jet break
  89. GRB050410: MASTER optical observations
  90. GRB 050410: Early observations with Swift-UVOT
  91. Swift-BAT detection of GRB 050410
  92. GRB 050410: Swift XRT Position
  93. GRB 050408: Properties of the Host Galaxy
  94. GRB 050408: Swift XRT analysis
  95. GRB 050408, optical observations
  96. GRB050408: REM NIR and Optical observation
  97. GRB 050408 Optical Observations
  98. GRB 050408: Optical afterglow confirmed
  99. GRB 050408, optical observations
  100. GRB 050408 optical candidate

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