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').

18342 results found.

  1. GRB071008: IAC80 observation
  2. GRB 071008: Swift detection of a burst
  3. GRB 071003: XRT refined analysis
  4. GRB070920A: MAGIC telescope GeV observation
  5. Radio detection of GRB 071003 with the VLA
  6. GRB 070810B: further XRT analysis
  7. Konus-Wind observation of GRB 071003
  8. GRB 071003: Swift XRT position
  9. GRB 071003, Swift-BAT refined analysis
  10. GRB 071003: MARGE Observations
  11. GRB 071003 Optical observations
  12. GRB 071003: KAIT optical afterglow observations
  13. GRB 071003: Swift detection of a bright burst
  14. GRB 070714B: host galaxy spectroscopic redshift
  15. GRB 071001: Swift-XRT Team refined analysis
  16. GRB 071001, Swift-BAT refined analysis
  17. Faulkes Telescope South observations of GRB 071001
  18. GRB 071001: Swift detection of a burst
  19. VLA observation of GRB 070923
  20. Disregard the Swift-XRT Notices today
  21. GRB070925: Swift-XRT Afterglow confirmation
  22. GRB070925: Swift-XRT Position
  23. Update on Swift Status
  24. GRB 070920B: ROTSE-III Early Optical Limits
  25. Recent SGR1806-20 Activity
  26. GRB 070923, Swift-BAT refined analysis
  27. GRB 070920B: XRT observations
  28. GRB 070923: Swift detection of a short hard burst
  29. GRB 070917: Suzaku/WAM observation of the prompt emission
  30. GRB 070920B: TAROT La Silla observatory optical observations
  31. GRB 070917: Confirmation of the X-ray afterglow
  32. GRB 070920B, Swift-BAT refined analysis
  33. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  34. GRB 070920B: NOT optical observations
  35. GRB 070920B: Swift detection of a burst
  36. GRB 070920, Swift-BAT refined analysis
  37. GRB 070920: TAROT Calern observatory optical observations
  38. GRB 070920: Swift detection of a burst
  39. SGR1806-20: Swift-BAT detection of enhanced activity
  40. GRB 070917: pseudo-z= 2.40 from prompt emission spectrum
  41. Konus-Wind observation of GRB 070917
  42. Swift Status and XRT Calibration Uncertainties
  43. GRB 070917: Swift-XRT observations
  44. GRB 070917: KAIT optical limits
  45. GRB 070917: R band observations
  46. GRB 070917, Swift-BAT refined analysis
  47. GRB 070917: Swift detection of a bright burst
  48. GRB 070911: Suzaku WAM observation of the prompt emission
  49. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  50. GRB 070809: The Swift evidence for the SHB nature of this burst
  51. GRB 070913: Swift-BAT refined analysis
  52. GRB 070913: Corrected BAT position
  53. GRB 070913: TAROT La Silla observatory optical observations
  54. GRB 070913: Swift detection of a burst
  55. Swift-BAT Notices back to autonomous real-time distribution
  56. GRB 070911: Swift XRT refined analysis
  57. GRB 070911, Swift-BAT refined analysis
  58. GRB 070911: Swift detection of a burst
  59. IPN search for a GRB associated with TAROT transient on August 31
  60. Intense burst from SGR 1806-20 detected on September 7
  61. GRB 070824 - Combined SuperAGILE/IPN Localization
  62. GRB 070731: Swift/UVOT Upper Limit
  63. GRB 070805: UVOT afterglow candidate retraction
  64. GRB070810b: optical candidate
  65. GRB 070810A: ROTSE-III Refined Analysis
  66. Swift observatory off line
  67. GRB070810B: Swift/UVOT Upper Limits
  68. GRB 070810B: XRT refined analysis
  69. GRB 070810B, Swift-BAT refined analysis
  70. GRB 070809: Swift/UVOT Corrected Photometry
  71. Swift Alert 070810.8: MASTER optical observation
  72. Swift Trigger 287421: False trigger due to star tracker loss
  73. GRB 070810A: Swift-BAT refined analysis
  74. GRB 070809: Swift/UVOT Upper Limits
  75. GRB 070810B: Swift detection of a short burst
  76. VLA upper limit on the short hard burst GRB 070729
  77. No radio detection in superAGILE burst 070724B
  78. GRB 070810: Swift-XRT Team Refined Analysis
  79. GRB 070809: Swift-XRT refined analysis
  80. GRB 070810: enhanced Swift-XRT position
  81. GRB 070810: Swift/UVOT Optical Counterpart
  82. GRB 070810: ROTSE-III Detection of Optical Counterpart
  83. GRB 070810: Swift detection of a burst
  84. GRB 070809, Swift-BAT refined analysis
  85. GRB 070808: Swift/UVOT upper limits
  86. GRB 070809: ROTSE-III Optical Limits
  87. GRB 070809: Swift detection of a short burst
  88. GCN Swift XRT update position notices and enhanced position circulars
  89. GRB 070808: Swift XRT refined analysis
  90. GRB 070808, Swift-BAT refined analysis
  91. GRB070808 - SDSS Pre-Burst Observations
  92. GRB 070808: ROTSE-III Optical Limits
  93. GRB 070808: Swift detection of a burst
  94. GRB070805 XRT and UVOT afterglow candidate
  95. Swift trigger on 4U 1700-377 while star tracker loss-of-lock
  96. Swift/UVOT observations of GRB070805
  97. GRB 070805, Swift-BAT refined analysis
  98. GRB 070805: Swift XRT initial analysis.
  99. GRB 070805: Swift/UVOT initial analysis
  100. GRB 070805: Swift detection of a burst

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