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"

28079 results found.

  1. GRB 091020: Swift detection of a burst with an optical afterglow
  2. GRB 091018: miniTAO/ANIR Observations
  3. GRB 091018: Skynet/PROMPT Observations of Fading
  4. GRB 091018 : Faulkes Telescope South Observations
  5. GRB 091018: BOOTES-3 observations
  6. GRB 091018: VLT/X-shooter spectra
  7. GRB091018: Swift/UVOT observations
  8. GRB 091018: GROND observations
  9. GRB091018: Magellan Echellette Observations
  10. GRB 091018: Enhanced Swift-XRT position
  11. GRB 091018: ROTSE-III Detection of Optical Counterpart
  12. GRB 091018: Swift detection of a burst with optical afterglow
  13. GRB 091003: Possible Supernova Component
  14. GRB 091003: Gemini-N redshift of possible host galaxy
  15. GRB 091010: optical obsevation
  16. GRB 091015: RTT150 optical observations
  17. GRB 090726 R band observations
  18. GRB 091010: optical afterglow candidate rejection
  19. GRB 091010: Swift-XRT refined analysis
  20. Radio observation of GRB090927 with ATCA
  21. Radio observation of GRB090926a with ATCA
  22. Radio observation of GRB080916c with ATCA
  23. GRB 091010: Fermi GBM observation
  24. GRB 091010: Faulkes Telescope North observations
  25. GRB 090531A: Skynet/PROMPT Observations
  26. GRB 090530A: Skynet/DSO Detections
  27. GRB 091010: RXTE detection
  28. GRB 091010: Enhanced XRT position
  29. GRB 091010 optical upper limits
  30. Detection of a short GRB 090929A by RT-2 Experiment
  31. GRB 091010: GROND afterglow candidate
  32. GRB 091010: Swift/UVOT Upper Limits
  33. GRB 091010: Swift-XRT position
  34. GRB 090926A: Skynet/PROMPT Observations of Day 6 - 11 Fading
  35. GRB 090518: Skynet/PROMPT Observations
  36. Short-Duration GRB 090621: Skynet/Dolomiti Observations
  37. GRB 090904A: afterglow confirmation
  38. GRB 090812: Skynet/PROMPT and GORT Observations
  39. GRB 091003: Lick observations and possible SDSS host galaxy
  40. GRB 090926B: Skynet/PROMPT Observations
  41. GRB 091003: WHT ACAM observations
  42. GRB 091003: Swift-XRT confirmation of fading afterglow
  43. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  44. GRB 091003: Skynet/DSO Observations
  45. GRB 091003: UVOT-enhanced XRT position
  46. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  47. GRB 091003: Swift XRT analysis
  48. GRB 091003A: Fermi LAT detection
  49. GRB 090926A: Skynet/PROMPT Observations of Day 4 - 6 Fading Rate
  50. GRB 091003A: Fermi GBM detection
  51. GRB 090926A: Skynet/PROMPT Observations of Post-Peak Fading
  52. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  53. GRB 090929A: Swift-XRT non-detection
  54. GRB 090929B: Swift-XRT refined analysis
  55. GRB 090929B: Gemini-N upper limits
  56. GRB 090929B: Skynet/DSO Observations
  57. GRB 090929B: Swift/UVOT Observations
  58. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  59. Correction: GRB 090929B: Enhanced Swift-XRT position
  60. GRB 090929: Enhanced Swift-XRT position
  61. GRB 090929B: Swift detection of a burst
  62. GRB 090929A: Fermi GBM detection
  63. GRB090926A: Swift-XRT refined analysis
  64. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  65. GRB 090927: VLT redshift
  66. GRB 090926B: Fermi GBM detection
  67. GRB 090927: Zadko Telescope observations
  68. Swift/UVOT observations of GRB 090927
  69. GRB 090926A: Skynet/PROMPT Continued Observations
  70. GRB 090927: Swift XRT refined analysis
  71. GRB 090927: Enhanced Swift-XRT position
  72. GRB090926B: Swift/UVOT Upper Limits
  73. GRB090926A: Swift/UVOT observations
  74. GRB 090926B: VLT spectroscopy
  75. GRB 090927: Swift/UVOT detection of an optical afterglow
  76. GRB 090927: Swift detection of a short burst
  77. GRB 090926B: optical object in error circle
  78. GRB 090926B: MAXI GSC detection
  79. GRB 090926A: VLT/X-shooter redshift
  80. GRB 090926B: Swift XRT refined analysis
  81. GRB 090926A: Swift/UVOT detection of an optical afterglow
  82. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  83. GRB090926A: UVOT-enhanced XRT position
  84. GRB 090926B: Swift detection of a burst
  85. GRB 090926: Fermi LAT detection
  86. GRB 090926: Fermi GBM detection
  87. GRB 090925: Fermi GBM detection
  88. GRB090904B : IRSF NIR upper limit
  89. GRB 090922A: Fermi GBM detection
  90. Swift returns to normal operations
  91. GRB 090715B: Skynet/PROMPT Detections
  92. GRB 090726: Skynet/GORT Observations
  93. GRB 090916: Swift-XRT upper limit
  94. GRB 090807: Skynet/DSO Observations
  95. GRB 090915: GROND upper limits
  96. GRB 090915: SARA detection of afterglow candidate
  97. GRB 090912: optical observation
  98. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  99. GRB 090702: Skynet/GORT Observations
  100. GRB 090902B: Skynet/PROMPT Observations

Advanced

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