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"

19544 results found.

  1. GRB 050520: Swift XRT position
  2. No Swift-BAT Lightcurves in real-time for next 3 weeks
  3. Swift-BAT trigger 122203 is not a real GRB
  4. GRB 050504: Swift XRT afterglow candidate has faded
  5. GRB 050509B: Subaru Optical Observations
  6. GRB050502b: Early Observation
  7. Refined Chandra analysis of GRB 050509b
  8. GRB050509b, SDSS pre-burst observations
  9. Chandra observation of GRB 050509b
  10. GRB 050509b: RAPTOR deep, early limits.
  11. GRB050509B: Optical/Infared observations
  12. GRB 050509b: Swift/UVOT follow-up measurements
  13. GRB 050509b Milagro GeV/TeV Observations
  14. GRB050509B: Optical observations at the Very Large Telescope
  15. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  16. GRB 050509a: Swift-BAT refined analysis
  17. GRB 050509B: WSRT Radio Observations
  18. GRB 050505: SARA Observations
  19. Swift UVOT Follow-up Observations of GRB 050509B
  20. GRB 050509B, Optical Observations
  21. GRB 050509B: Swift/XRT refined analysis
  22. GRB050509a: Swift UVOT observations
  23. GRB 050509b: Optical observations
  24. GRB 050509b: Possible Optical Counterpart
  25. GRB 050509A: Optical observations
  26. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  27. GRB 050509b: optical observations
  28. GRB 050509b: Swift XRT Position
  29. GRB 050509B: ROTSE-III Optical Limits
  30. Swift Detection of GRB050509b: A short duration burst
  31. GRB 050509a: Swift XRT Position
  32. Swift Detection of the Burst GRB050509
  33. Swift-BAT detection of GRB 050507
  34. GRB 050505: early time observations
  35. GRB 050505 - Faulkes Telescope North observations
  36. GRB 050502a: Swift XRT Upper Limit
  37. GRB 050505, simultaneous optical observation
  38. GRB 050505: Further Swift UVOT observations.
  39. GRB050416A : 1 GHz limit from GMRT
  40. GRB 050505 UVOT
  41. GRB 050505: Swift XRT Position
  42. GRB050505 Swift-BAT refined analysis
  43. GRB 050416b:Swift XRT afterglow upper limits
  44. GRB 050416b:Swift XRT afterglow upper limits
  45. Swift-BAT detection of GRB050505
  46. GRB 050504: Swift XRT position
  47. Swift UVOT observation of GRB 050504
  48. GRB 050502b, V band Observations
  49. Renewal of SGR 1806-20 activity
  50. GRB050502B Swift-BAT refined analysis
  51. GRB050502B: I band source in XRT error circle
  52. Swift UVOT refined analysis
  53. Retraction of Swift-BAT trigger 116145
  54. GRB 050502b : optical observation at Lulin observatory
  55. GRB 050502b: Swift XRT Position
  56. GRB050502B: Optical Limits from ANU 1m
  57. Swift Detection of the Bright Burst GRB050502b
  58. GRB050502: ANU 1m optical Observations
  59. Swift-BAT Trigger 115881 is not a real GRB
  60. Swift/BAT possible detection of a weak burst GRB050430
  61. GRB 050401: Rc observation
  62. GRB050416a: Radio Detection
  63. GRB 050422: Swift-UVOT observation
  64. GRB 050422: Swift-BAT refined analysis
  65. GRB 050422: Swift XRT Position
  66. Swift Detection of GRB 050422
  67. GRB 050421: SLOTIS observations
  68. GRB050421: Radio Observations
  69. GRB050421: Radio Observations
  70. GRB 050421: Swift-UVOT observation
  71. GRB 050421: Swift-BAT refined analysis
  72. GRB 050421: ROTSE-III Optical Limits
  73. GRB 050421: early Swift XRT analysis results
  74. GRB 050421: BOOTES-2 simultaneous optical observations
  75. GRB 050421: Optical observations at the INT
  76. Swift Detection of GRB050421
  77. GRB 050416b: Tentative Swift XRT Position
  78. GRB050326: analysis of the XMM-Newton observation
  79. GRB 050418: Swift-BAT refined analysis
  80. Swift-BAT detection of the bright and long GRB 050418
  81. GRB 050416B: optical observations
  82. GRB 050416b: Swift-BAT refined analysis
  83. GRB 050416: Swift/UVOT refined analysis
  84. Swift-BAT detection of GRB 050416b
  85. GRB050412: Radio Observations
  86. GRB 050416: Swift/UVOT detection of afterglow emission
  87. GRB050416: Refined Swift-XRT analysis
  88. GRB050416: Maidanak optical observations
  89. GRB 050416: Swift-BAT refined analysis
  90. GRB 050416,optical observation
  91. GRB 050416: KAIT observations
  92. GRB 050416: Swift XRT Position
  93. GRB 050416: Radio observations
  94. Confirmation of OT for GRB050416
  95. GRB050416: P60 Afterglow Candidate
  96. Swift BAT/XRT Detection of GRB 050416
  97. GRB 050412: Subaru observations
  98. GRB 050412: optical limit
  99. GRB 050412: optical observations
  100. GRB 050408: refined XRT analysis, no jet break seen yet

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