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"

21772 results found.

  1. GRB 091026: Enhanced Swift-XRT position
  2. GRB 091026: Swift detection of a Gamma Ray Burst
  3. GRB091024 Swift/UVOT Upper Limits
  4. GRB 091024: Super-LOTIS early observations
  5. GRB 091024: Fermi GBM Observations
  6. GRB 091024: Swift-XRT team refined analysis
  7. GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
  8. GRB 091024: GRAS004 optical observations
  9. Konus-Wind observations of GRB 091010
  10. GRB091020 Swift/UVOT observations
  11. GRB 091020: Enhanced Swift-XRT position
  12. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  13. GRB 091020: Swift detection of a burst with an optical afterglow
  14. GRB 091018: Skynet/PROMPT Observations of Fading
  15. Konus-RF observation of GRB 091018
  16. GRB 091018 : Faulkes Telescope South Observations
  17. GRB 091018: BOOTES-3 observations
  18. GRB091018: Swift/UVOT observations
  19. GRB 091018: Swift-BAT refined analysis
  20. GRB 091018: Enhanced Swift-XRT position
  21. GRB 091015: Skynet/PROMPT Observations
  22. GRB 091018: Swift detection of a burst with optical afterglow
  23. GRB 091010: optical obsevation
  24. GRB 091010: Swift-XRT refined analysis
  25. GRB 091010: Suzaku WAM observation of the prompt emission
  26. Radio observation of GRB090927 with ATCA
  27. Radio observation of GRB090926a with ATCA
  28. Radio observation of GRB080916c with ATCA
  29. GRB 091010: Fermi GBM observation
  30. GRB 090531A: Skynet/PROMPT Observations
  31. GRB 091010: Enhanced XRT position
  32. GRB 091010 optical upper limits
  33. Detection of a short GRB 090929A by RT-2 Experiment
  34. GRB 091010: GROND afterglow candidate
  35. GRB 091010: Swift/UVOT Upper Limits
  36. GRB 090518: Skynet/PROMPT Observations
  37. GRB 090904A: afterglow confirmation
  38. GRB 090812: Skynet/PROMPT and GORT Observations
  39. GRB 091003A: Suzaku WAM observation of the prompt emission
  40. GRB 090926B: Skynet/PROMPT Observations
  41. GRB 091003: WHT ACAM observations
  42. Konus-Wind observation of GRB 091003A
  43. GRB 090929B: Suzaku WAM observation of the prompt emission
  44. GRB 090929A: Suzaku WAM observation of the prompt emission
  45. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  46. GRB 091003: UVOT-enhanced XRT position
  47. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  48. GRB 091003A: Fermi LAT detection
  49. GRB 090929A, Swift-BAT refined analysis
  50. GRB 090929B, Swift-BAT refined analysis
  51. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  52. Konus-Wind observation of GRB 090929A
  53. Konus-Wind observation of GRB 090929B
  54. GRB 090929B: Gemini-N upper limits
  55. GRB 090929B: Swift/UVOT Observations
  56. Konus-RF observation of GRB 090929A
  57. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  58. Correction: GRB 090929B: Enhanced Swift-XRT position
  59. GRB 090929: Enhanced Swift-XRT position
  60. GRB 090929B: Swift detection of a burst
  61. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  62. Konus-Wind and Konus-RF observations of GRB 090926A
  63. GRB 090927: Zadko Telescope observations
  64. Swift/UVOT observations of GRB 090927
  65. GRB 090927: Swift XRT refined analysis
  66. GRB 090926A: Suzaku WAM observation of the prompt emission
  67. GRB 090927: Enhanced Swift-XRT position
  68. GRB090926B: Swift/UVOT Upper Limits
  69. GRB090926A: Swift/UVOT observations
  70. GRB 090926B: optical object in error circle
  71. GRB 090926B: NOT optical observation
  72. GRB 090926B: Swift XRT refined analysis
  73. GRB 090926A: Swift/UVOT detection of an optical afterglow
  74. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  75. GRB090926A: UVOT-enhanced XRT position
  76. GRB 090926B: Swift detection of a burst
  77. GRB 090926: Fermi LAT detection
  78. GRB 090715B: Skynet/PROMPT Detections
  79. GRB 090916: Swift-XRT upper limit
  80. GRB 090915: GROND upper limits
  81. Short-Duration GRB 090916: Skynet/PROMPT Observations
  82. GRB 090915: SARA detection of afterglow candidate
  83. GRB 090912: optical observation
  84. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  85. GRB 090902B: Skynet/PROMPT Observations
  86. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  87. GRB 090915 Swift-BAT detection of a burst in ground analysis
  88. GRB 090827: Confirmation of the X-ray afterglow
  89. GRB 090912: Swift/UVOT Upper Limits
  90. GRB 090912 optical upper limit
  91. GRB 090912: Enhanced Swift-XRT position
  92. GRB 090912: Swift detection of a burst
  93. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  94. GRB 090904B: GROND detection of the optical afterglow
  95. GRB 090831A: Suzaku WAM observation of the prompt emission
  96. GRB 090904B: Swift/UVOT Refined Analysis
  97. GRB 090902B: Suzaku WAM observation of the prompt emission
  98. GRB 090829A: Suzaku WAM observation of the prompt emission
  99. GRB 090904A: Enhanced Swift XRT position
  100. GRB 090904B: Swift-BAT refined analysis

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov