Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

19603 results found.

  1. Swift UVOT upper limits
  2. GRB 071025: Swift-XRT Team refined analysis
  3. GRB 071025, Swift-BAT refined analysis
  4. GRB 071025: Early Super-LOTIS Observations
  5. GRB 071025: ROTSE-III Refined Analysis
  6. GRB 071025: Swift XRT refined position
  7. GRB 071025: ROTSE-III Detection of Optical Counterpart
  8. GRB 071025: Swift detection of a burst
  9. GRB 071020: BTA spectroscopy
  10. Possible radio detection of GRB 071021 with the VLA
  11. Radio detection of GRB 071020 with the VLA
  12. GRB 071021: optical and NIR observations
  13. GRB 071021, Swift-BAT refined analysis
  14. GRB 071021: Swift-XRT Team refined analysis
  15. Konus-Wind observation of GRB 071020
  16. GRB 071021: Swift detection of a burst
  17. GRB 071020: Swift-XRT refined analysis
  18. GRB 071020, Swift-BAT refined analysis
  19. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  20. GRB071020 - SDSS Pre-burst Observations
  21. GRB 071020: Swift detection of a bright burst
  22. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  23. GRB 071018: Mercator Telescope optical observations
  24. Swift autonomous slewing re-enabled
  25. GRB 071018: Swift-XRT observation
  26. GRB 071017 - Swift XRT observations
  27. VLA radio observation of GRB 071018
  28. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  29. GRB 071018, Swift-BAT refined analysis
  30. GRB 071018?: Swift detection of a possible burst
  31. GRB 071010B: Suzaku WAM observation of the prompt emission
  32. GRB 071013: 3rd TLS Epoch - constraints on variability
  33. GRB 071013: TLS Upper Limit
  34. VLA detection of radio afterglow of GRB 071010B
  35. VLA non-detection of GRB 071011
  36. GRB 071013: Optical observations
  37. GRB 071013, Swift-BAT refined analysis
  38. GRB 071013: Swift detection of a burst
  39. GRB 071010C Swift-BAT detection of a burst
  40. GRB 071011: Swift-XRT refined analysis
  41. VLA non-detection of GRB 071010A
  42. GRB 071011, Optical afterglow
  43. GRB 071011: MARGE Optical Limits
  44. GRB 071011: XRT afterglow detection
  45. GRB 071011, Swift-BAT refined analysis
  46. GRB 071011: Early Super-LOTIS Observations
  47. GRB 071010B: Bright OT confirmed with TLS
  48. GRB 071011: Swift detection of a burst
  49. Optical Observation: GRB 071010
  50. Optical observations: GRB 071010A
  51. Konus-Wind observation of GRB 071010B
  52. GRB071010B: Swift/XRT detection
  53. GRB 071010B, Swift-BAT refined analysis
  54. GRB 071006, Swift-BAT refined analysis
  55. GRB 071010B: Swift detection of a burst
  56. GRB 071010: Swift-XRT observation
  57. GRB 071008, Swift-BAT refined analysis
  58. GRB 071010, Swift-BAT refined analysis
  59. GRB071008: Swift-XRT observation
  60. GRB 071010: TAROT La Silla observatory detection of the afterglow
  61. GRB 071010: Swift detection of a burst
  62. GRB 071006 Swift-BAT detection of a burst
  63. GRB071008: IAC80 observation
  64. GRB 071008: Swift detection of a burst
  65. GRB 071003: XRT refined analysis
  66. GRB070920A: MAGIC telescope GeV observation
  67. Radio detection of GRB 071003 with the VLA
  68. GRB 070810B: further XRT analysis
  69. Konus-Wind observation of GRB 071003
  70. GRB 071003: Swift XRT position
  71. GRB 071003, Swift-BAT refined analysis
  72. GRB 071003: MARGE Observations
  73. GRB 071003 Optical observations
  74. GRB 071003: KAIT optical afterglow observations
  75. GRB 071003: Swift detection of a bright burst
  76. GRB 070714B: host galaxy spectroscopic redshift
  77. GRB 071001: Swift-XRT Team refined analysis
  78. GRB 071001, Swift-BAT refined analysis
  79. Faulkes Telescope South observations of GRB 071001
  80. GRB 071001: Swift detection of a burst
  81. VLA observation of GRB 070923
  82. Disregard the Swift-XRT Notices today
  83. GRB070925: Swift-XRT Afterglow confirmation
  84. GRB070925: Swift-XRT Position
  85. Update on Swift Status
  86. GRB 070920B: ROTSE-III Early Optical Limits
  87. Recent SGR1806-20 Activity
  88. GRB 070923, Swift-BAT refined analysis
  89. GRB 070920B: XRT observations
  90. GRB 070923: Swift detection of a short hard burst
  91. GRB 070917: Suzaku/WAM observation of the prompt emission
  92. GRB 070920B: TAROT La Silla observatory optical observations
  93. GRB 070917: Confirmation of the X-ray afterglow
  94. GRB 070920B, Swift-BAT refined analysis
  95. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  96. GRB 070920B: NOT optical observations
  97. GRB 070920B: Swift detection of a burst
  98. GRB 070920, Swift-BAT refined analysis
  99. GRB 070920: TAROT Calern observatory optical observations
  100. GRB 070920: Swift detection of a burst

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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