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"

19353 results found.

  1. GRB050421: Radio Observations
  2. GRB050421: Radio Observations
  3. GRB 050421: Swift-UVOT observation
  4. GRB 050421: Swift-BAT refined analysis
  5. GRB 050421: ROTSE-III Optical Limits
  6. GRB 050421: early Swift XRT analysis results
  7. GRB 050421: BOOTES-2 simultaneous optical observations
  8. GRB 050421: Optical observations at the INT
  9. Swift Detection of GRB050421
  10. GRB 050416b: Tentative Swift XRT Position
  11. GRB050326: analysis of the XMM-Newton observation
  12. GRB 050418: Swift-BAT refined analysis
  13. Swift-BAT detection of the bright and long GRB 050418
  14. GRB 050416B: optical observations
  15. GRB 050416b: Swift-BAT refined analysis
  16. GRB 050416: Swift/UVOT refined analysis
  17. Swift-BAT detection of GRB 050416b
  18. GRB050412: Radio Observations
  19. GRB 050416: Swift/UVOT detection of afterglow emission
  20. GRB050416: Refined Swift-XRT analysis
  21. GRB050416: Maidanak optical observations
  22. GRB 050416: Swift-BAT refined analysis
  23. GRB 050416,optical observation
  24. GRB 050416: KAIT observations
  25. GRB 050416: Swift XRT Position
  26. GRB 050416: Radio observations
  27. Confirmation of OT for GRB050416
  28. GRB050416: P60 Afterglow Candidate
  29. Swift BAT/XRT Detection of GRB 050416
  30. GRB 050412: Subaru observations
  31. GRB 050412: optical limit
  32. GRB 050412: optical observations
  33. GRB 050408: refined XRT analysis, no jet break seen yet
  34. GRB 050412: early Swift XRT analysis results
  35. GRB 050412: Swift-BAT refined analysis
  36. GRB 050412: ANU 2.3m observations
  37. GRB 050412: Early Optical/Ultraviolet Observations with
  38. GRB 050412: retraction of UVOT transient report
  39. GRB 050412: UVOT transient not in XRT error circle
  40. GRB 050412: Swift XRT Position
  41. GRB050412: optical limit before and during GRB
  42. GRB050412: ROTSE-III Optical Limits
  43. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  44. GRB 050412: IR Observations
  45. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  46. GRB 050410, optical observations
  47. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  48. GRB 050410 R band Optical Observations
  49. GRB050410 : Null detection report
  50. GRB 050410, optical observations
  51. GRB050410: Radio Observations
  52. GRB 050408: Swift XRT measurement of possible jet break
  53. GRB050410: MASTER optical observations
  54. GRB 050410: Early observations with Swift-UVOT
  55. Swift-BAT detection of GRB 050410
  56. GRB 050410: Swift XRT Position
  57. GRB 050408: Properties of the Host Galaxy
  58. GRB 050408: Swift XRT analysis
  59. GRB 050408, optical observations
  60. GRB050408: REM NIR and Optical observation
  61. GRB 050408 Optical Observations
  62. GRB 050408: Optical afterglow confirmed
  63. GRB 050408, optical observations
  64. GRB 050408 optical candidate
  65. GRB 050408: Swift XRT Position
  66. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  67. GRB 050406: early Swift XRT analysis results
  68. GRB 050406 BAT refined analysis
  69. GRB 050406: Early observations with Swift-UVOT
  70. GRB 050406: Swift XRT Position
  71. Swift-BAT detection of GRB 050406
  72. Konus-Wind observation of GRB 050401
  73. GRB050401: Radio observation at 610 MHz with GMRT
  74. GRB 050401: VLT spectroscopic redshift
  75. GRB 050401 Optical Observations
  76. GRB050401: Maidanak optical observation
  77. GRB 050401 BAT refined analysis
  78. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  79. GRB 050402A: IR Observations
  80. GRB 050402: Early observations with Swift-UVOT
  81. Swift Trigger 113225: P60 Observations
  82. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  83. GRB 050401: Optical afterglow candidate
  84. Swift-BAT detection of GRB 050401
  85. GRB 050401: Prompt XRT position
  86. Retraction of three Swift GRB triggers
  87. Swift-BAT detection of GRB 050331b
  88. GRB 050331: Swift UVOT Source
  89. Swift-BAT detection of GRB 050331
  90. GRB 050331: Swift XRT Position
  91. Swift Data Publicly Available Starting April 5, 2005
  92. Konus-Wind observation of GRB 050326
  93. GRB050326: optical limit
  94. GRB 050326: Early observations with Swift-UVOT
  95. GRB 050326 XMM-Newton observation
  96. GRB 050326 : Planned XMM-Newton observation
  97. GRB 050326: Swift XRT Position
  98. GRB050326: optical limit 33min before GRB
  99. GRB 050326 BAT refined analysis
  100. GRB050326: delayed XRT observation

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