Skip to main content
Circulars over Kafka event name backfill. 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"

18695 results found.

  1. GRB050502B Swift-BAT refined analysis
  2. GRB050502B: I band source in XRT error circle
  3. Swift UVOT refined analysis
  4. Retraction of Swift-BAT trigger 116145
  5. GRB 050502b : optical observation at Lulin observatory
  6. GRB 050502b: Swift XRT Position
  7. GRB050502B: Optical Limits from ANU 1m
  8. Swift Detection of the Bright Burst GRB050502b
  9. GRB050502: ANU 1m optical Observations
  10. Swift-BAT Trigger 115881 is not a real GRB
  11. Swift/BAT possible detection of a weak burst GRB050430
  12. GRB 050401: Rc observation
  13. GRB050416a: Radio Detection
  14. GRB 050422: Swift-UVOT observation
  15. GRB 050422: Swift-BAT refined analysis
  16. GRB 050422: Swift XRT Position
  17. Swift Detection of GRB 050422
  18. GRB 050421: SLOTIS observations
  19. GRB050421: Radio Observations
  20. GRB050421: Radio Observations
  21. GRB 050421: Swift-UVOT observation
  22. GRB 050421: Swift-BAT refined analysis
  23. GRB 050421: ROTSE-III Optical Limits
  24. GRB 050421: early Swift XRT analysis results
  25. GRB 050421: BOOTES-2 simultaneous optical observations
  26. GRB 050421: Optical observations at the INT
  27. Swift Detection of GRB050421
  28. GRB 050416b: Tentative Swift XRT Position
  29. GRB050326: analysis of the XMM-Newton observation
  30. GRB 050418: Swift-BAT refined analysis
  31. Swift-BAT detection of the bright and long GRB 050418
  32. GRB 050416B: optical observations
  33. GRB 050416b: Swift-BAT refined analysis
  34. GRB 050416: Swift/UVOT refined analysis
  35. Swift-BAT detection of GRB 050416b
  36. GRB050412: Radio Observations
  37. GRB 050416: Swift/UVOT detection of afterglow emission
  38. GRB050416: Refined Swift-XRT analysis
  39. GRB050416: Maidanak optical observations
  40. GRB 050416: Swift-BAT refined analysis
  41. GRB 050416,optical observation
  42. GRB 050416: KAIT observations
  43. GRB 050416: Swift XRT Position
  44. GRB 050416: Radio observations
  45. Confirmation of OT for GRB050416
  46. GRB050416: P60 Afterglow Candidate
  47. Swift BAT/XRT Detection of GRB 050416
  48. GRB 050412: Subaru observations
  49. GRB 050412: optical limit
  50. GRB 050412: optical observations
  51. GRB 050408: refined XRT analysis, no jet break seen yet
  52. GRB 050412: early Swift XRT analysis results
  53. GRB 050412: Swift-BAT refined analysis
  54. GRB 050412: ANU 2.3m observations
  55. GRB 050412: Early Optical/Ultraviolet Observations with
  56. GRB 050412: retraction of UVOT transient report
  57. GRB 050412: UVOT transient not in XRT error circle
  58. GRB 050412: Swift XRT Position
  59. GRB050412: optical limit before and during GRB
  60. GRB050412: ROTSE-III Optical Limits
  61. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  62. GRB 050412: IR Observations
  63. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  64. GRB 050410, optical observations
  65. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  66. GRB 050410 R band Optical Observations
  67. GRB050410 : Null detection report
  68. GRB 050410, optical observations
  69. GRB050410: Radio Observations
  70. GRB 050408: Swift XRT measurement of possible jet break
  71. GRB050410: MASTER optical observations
  72. GRB 050410: Early observations with Swift-UVOT
  73. Swift-BAT detection of GRB 050410
  74. GRB 050410: Swift XRT Position
  75. GRB 050408: Properties of the Host Galaxy
  76. GRB 050408: Swift XRT analysis
  77. GRB 050408, optical observations
  78. GRB050408: REM NIR and Optical observation
  79. GRB 050408 Optical Observations
  80. GRB 050408: Optical afterglow confirmed
  81. GRB 050408, optical observations
  82. GRB 050408 optical candidate
  83. GRB 050408: Swift XRT Position
  84. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  85. GRB 050406: early Swift XRT analysis results
  86. GRB 050406 BAT refined analysis
  87. GRB 050406: Early observations with Swift-UVOT
  88. GRB 050406: Swift XRT Position
  89. Swift-BAT detection of GRB 050406
  90. Konus-Wind observation of GRB 050401
  91. GRB050401: Radio observation at 610 MHz with GMRT
  92. GRB 050401: VLT spectroscopic redshift
  93. GRB 050401 Optical Observations
  94. GRB050401: Maidanak optical observation
  95. GRB 050401 BAT refined analysis
  96. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  97. GRB 050402A: IR Observations
  98. GRB 050402: Early observations with Swift-UVOT
  99. Swift Trigger 113225: P60 Observations
  100. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart

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