Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. 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').

17112 results found.

  1. GRB050509b, SDSS pre-burst observations
  2. Chandra observation of GRB 050509b
  3. GRB 050509b: RAPTOR deep, early limits.
  4. GRB050509B: Optical/Infared observations
  5. GRB 050509b: Swift/UVOT follow-up measurements
  6. GRB 050509b Milagro GeV/TeV Observations
  7. GRB050509B: Optical observations at the Very Large Telescope
  8. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  9. GRB 050509a: Swift-BAT refined analysis
  10. GRB 050509B: WSRT Radio Observations
  11. GRB 050505: SARA Observations
  12. Swift UVOT Follow-up Observations of GRB 050509B
  13. GRB 050509B, Optical Observations
  14. GRB 050509B: Swift/XRT refined analysis
  15. GRB050509a: Swift UVOT observations
  16. GRB 050509b: Optical observations
  17. GRB 050509b: Possible Optical Counterpart
  18. GRB 050509A: Optical observations
  19. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  20. GRB 050509b: optical observations
  21. GRB 050509b: Swift XRT Position
  22. GRB 050509B: ROTSE-III Optical Limits
  23. Swift Detection of GRB050509b: A short duration burst
  24. GRB 050509a: Swift XRT Position
  25. Swift Detection of the Burst GRB050509
  26. Swift-BAT detection of GRB 050507
  27. GRB 050505: early time observations
  28. GRB 050505 - Faulkes Telescope North observations
  29. GRB 050502a: Swift XRT Upper Limit
  30. GRB 050505, simultaneous optical observation
  31. GRB 050505: Further Swift UVOT observations.
  32. GRB050416A : 1 GHz limit from GMRT
  33. GRB 050505 UVOT
  34. GRB 050505: Swift XRT Position
  35. GRB050505 Swift-BAT refined analysis
  36. GRB 050416b:Swift XRT afterglow upper limits
  37. GRB 050416b:Swift XRT afterglow upper limits
  38. Swift-BAT detection of GRB050505
  39. GRB 050504: Swift XRT position
  40. Swift UVOT observation of GRB 050504
  41. GRB 050502b, V band Observations
  42. GRB050502B Swift-BAT refined analysis
  43. GRB050502B: I band source in XRT error circle
  44. Swift UVOT refined analysis
  45. Retraction of Swift-BAT trigger 116145
  46. GRB 050502b : optical observation at Lulin observatory
  47. GRB 050502b: Swift XRT Position
  48. GRB050502B: Optical Limits from ANU 1m
  49. Swift Detection of the Bright Burst GRB050502b
  50. GRB050502: ANU 1m optical Observations
  51. Swift-BAT Trigger 115881 is not a real GRB
  52. Swift/BAT possible detection of a weak burst GRB050430
  53. GRB 050401: Rc observation
  54. GRB050416a: Radio Detection
  55. GRB 050422: Swift-UVOT observation
  56. GRB 050422: Swift-BAT refined analysis
  57. GRB 050422: Swift XRT Position
  58. Swift Detection of GRB 050422
  59. GRB 050421: SLOTIS observations
  60. GRB050421: Radio Observations
  61. GRB050421: Radio Observations
  62. GRB 050421: Swift-UVOT observation
  63. GRB 050421: Swift-BAT refined analysis
  64. GRB 050421: ROTSE-III Optical Limits
  65. GRB 050421: early Swift XRT analysis results
  66. GRB 050421: BOOTES-2 simultaneous optical observations
  67. GRB 050421: Optical observations at the INT
  68. Swift Detection of GRB050421
  69. GRB 050416b: Tentative Swift XRT Position
  70. GRB050326: analysis of the XMM-Newton observation
  71. GRB 050418: Swift-BAT refined analysis
  72. Swift-BAT detection of the bright and long GRB 050418
  73. GRB 050416B: optical observations
  74. GRB 050416b: Swift-BAT refined analysis
  75. GRB 050416: Swift/UVOT refined analysis
  76. Swift-BAT detection of GRB 050416b
  77. GRB050412: Radio Observations
  78. GRB 050416: Swift/UVOT detection of afterglow emission
  79. GRB050416: Refined Swift-XRT analysis
  80. GRB050416: Maidanak optical observations
  81. GRB 050416: Swift-BAT refined analysis
  82. GRB 050416,optical observation
  83. GRB 050416: KAIT observations
  84. GRB 050416: Swift XRT Position
  85. GRB 050416: Radio observations
  86. Confirmation of OT for GRB050416
  87. GRB050416: P60 Afterglow Candidate
  88. Swift BAT/XRT Detection of GRB 050416
  89. GRB 050412: Subaru observations
  90. GRB 050412: optical limit
  91. GRB 050412: optical observations
  92. GRB 050408: refined XRT analysis, no jet break seen yet
  93. GRB 050412: early Swift XRT analysis results
  94. GRB 050412: Swift-BAT refined analysis
  95. GRB 050412: ANU 2.3m observations
  96. GRB 050412: Early Optical/Ultraviolet Observations with
  97. GRB 050412: retraction of UVOT transient report
  98. GRB 050412: UVOT transient not in XRT error circle
  99. GRB 050412: Swift XRT Position
  100. GRB050412: optical limit before and during GRB

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