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"

8477 results found.

  1. GRB 090313: Swift-XRT refined analysis
  2. GRB 090313, GROND observations
  3. GRB 090313 OA candidate
  4. GRB 090205: Zadko Telescope late-time observations
  5. GRB 090309: Swift detection of a burst
  6. GRB 090307B: Fermi GBM detection
  7. GRB 090308: Swift detection of a burst
  8. Swift Trigger 345551 is probably not a GRB
  9. GRB090305: GMOS-S Candidate Optical Afterglow
  10. GRB 090305: Swift detection of a short burst
  11. GRB 090227: Fermi GBM detection
  12. SGR J1550-5418
  13. GRB 090205: Swift/UVOT Upper Limits
  14. GRB 090205: VLT candidate afterglow
  15. GRB 090205: Swift detection of a burst
  16. GRB090201: Swift UVOT upper limits
  17. GRB 090201: VLT NIR observations
  18. GRB 090201: VLT afterglow candidate
  19. GRB 090129: Swift detection of a burst
  20. GRB 090126: SuperAGILE Localization of a Long GRB
  21. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  22. GRB 090118: no afterglow candidate
  23. GRB 090123: Swift detection of a burst
  24. Trigger 340734: Swift detection of a possible short burst
  25. GRB 090118: Subaru NIR Observation
  26. GRB 090118: KPNO 4m 2nd Epoch Observations
  27. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  28. GRB090118 Swift/UVOT upper limits
  29. GRB 090118: Possible burst detection from Swift-BAT slew data
  30. GRB090117: Swift-XRT detection of a possible candidate afterglow
  31. GRB 090117 - SuperAGILE Localization of a long GRB
  32. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  33. GRB 090113: Swift detection of a burst
  34. GRB 090111: Swift detection of a burst
  35. GRB 090102: WSRT Radio Observations
  36. GRB 090107B: Swift/UVOT Observations
  37. Swift UVOT observations of GRB 090102
  38. GRB 090102: Swift detection of a burst with an optical counterpart
  39. GRB 081230: GROND confirmation of the afterglow
  40. GRB 081230: Swift detection of a burst
  41. GRB 081228: GROND confirmation of the optical/NIR afterglow
  42. GRB 081228: Swift detection of a burst
  43. GRB 081226B: Swift XRT and UVOT upper limits
  44. GRB 081224: Suzaku WAM observation of the prompt emission
  45. GRB 081226: GROND afterglow candidate
  46. GRB 081222: MITSuME optical observation
  47. GRB 081224: Fermi GBM Detection & LAT Localization
  48. GRB 081222:Optical afterglow observation
  49. GRB081222: REM candidate afterglow
  50. GRB 081222: Swift detection of a burst with a bright optical afterglow
  51. GRB 081221: Swift detection of a burst
  52. GRB 081118: Zadko observations
  53. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  54. GRB 081211: Swift detection of a burst
  55. GRB 081210: Swift detection of a burst with optical afterglow
  56. GRB 081128: afterglow observations
  57. GRB 081128: Optical afterglow observations
  58. GRB 081204: GROND Observations
  59. GRB 081204: Swift XRT afterglow confirmation
  60. GRB 081204: Swift XRT afterglow candidate
  61. GRB 081203B: Swift-XRT candidate afterglow.
  62. GRB 081203A: Burst detection from Swift-BAT slew data
  63. GRB 081203: Swift detection of a burst with a bright optical counterpart
  64. Trigger 335971: Swift possible detection of a burst
  65. GRB 081128: Liverpool Telescope afterglow confirmation
  66. GRB 081128: Swift detection of a burst
  67. GRB 081127: Swift detection of a burst
  68. GRB 081126: Swift detection of a burst
  69. GRB081121: Swift/UVOT observations
  70. GRB 081121: ROTSE-III Detection of Optical Counterpart
  71. GRB 081118: VLT redshift
  72. GRB 081118: optical afterglow candidate
  73. GRB 081118: Swift detection of a burst
  74. GRB 081110: Fermi GBM detection
  75. GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
  76. GRB 081109: Swift detection of a burst
  77. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  78. GRB 081102: Swift detection of a burst
  79. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  80. GRB 081024B: new Swift-XRT observations
  81. GRB 081029: ROTSE-III Detection of Optical Counterpart
  82. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  83. GRB 081028: Swift detection of a burst
  84. GRB 081025: TLS upper limits
  85. GRB 081025 BAT refined analysis
  86. GRB 081025: Burst detection from Swift-BAT slew data
  87. GRB 081024: Swift detection of a burst
  88. Swift detection of a possible burst (trigger 332287)
  89. GRB 081017: REM early observations
  90. GRB 081016B: Swift detection of a burst
  91. GRB 081016: Swift-XRT candidate afterglow detection
  92. GRB 081008: Galaxy associated with z=1.967 absorber
  93. GRB 081011: Swift detection of a burst
  94. GRB 081008: Swift detection of a burst with optical afterglow
  95. GRB 081007: Swift detection of a burst with optical afterglow
  96. Trigger 330353: Swift detection of a Galactic short soft burst
  97. GRB081001: SuperAGILE Localization of a long GRB
  98. GRB 080928: Swift detection of a burst with an optical counterpart
  99. GRB 080920: Fermi GBM detection
  100. Swift trigger 325707: Swift/UVOT Upper Limits

Advanced

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