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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"

28048 results found.

  1. GRB 090929B: Swift/UVOT Observations
  2. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  3. GRB 090929A BAT location of the Fermi GBM burst
  4. Correction: GRB 090929B: Enhanced Swift-XRT position
  5. GRB 090929: Enhanced Swift-XRT position
  6. GRB 090929B: Swift detection of a burst
  7. GRB 090929A: Fermi GBM detection
  8. GRB090926A: Swift-XRT refined analysis
  9. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  10. GRB 090927: Zadko Telescope observations
  11. GRB 090927, Swift-BAT refined analysis of the possibly short burst
  12. Swift/UVOT observations of GRB 090927
  13. GRB 090926A: Skynet/PROMPT Continued Observations
  14. GRB 090927: Swift XRT refined analysis
  15. GRB 090926A: Suzaku WAM observation of the prompt emission
  16. GRB 090927: Enhanced Swift-XRT position
  17. GRB090926B: Swift/UVOT Upper Limits
  18. GRB090926A: Swift/UVOT observations
  19. GRB 090927: Swift/UVOT detection of an optical afterglow
  20. GRB 090927: Swift detection of a short burst
  21. GRB 090926B: optical object in error circle
  22. GRB 090926B: MAXI GSC detection
  23. GRB 090926B: NOT optical observation
  24. GRB 090926B: Swift XRT refined analysis
  25. GRB 090926B: Swift-BAT refined analysis
  26. GRB 090926A: Swift/UVOT detection of an optical afterglow
  27. GRB090926A: UVOT-enhanced XRT position
  28. GRB 090926B: Swift detection of a burst
  29. GRB 090926: Fermi LAT detection
  30. GRB 090926: Fermi GBM detection
  31. GRB 090925: Fermi GBM detection
  32. GRB090922A: correction to Fermi location
  33. GRB 090922A: Fermi GBM detection
  34. GRB 090715B: Skynet/PROMPT Detections
  35. GRB 090726: Skynet/GORT Observations
  36. GRB 090916: Swift-XRT upper limit
  37. GRB 090807: Skynet/DSO Observations
  38. GRB 090915: GROND upper limits
  39. Short-Duration GRB 090916: Skynet/PROMPT Observations
  40. GRB 090915: SARA detection of afterglow candidate
  41. GRB 090912: optical observation
  42. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  43. GRB 090702: Skynet/GORT Observations
  44. GRB 090902B: Skynet/PROMPT Observations
  45. GRB 090916, Swift-BAT refined analysis
  46. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  47. GRB 090915 Swift-BAT detection of a burst in ground analysis
  48. GRB 090827: Confirmation of the X-ray afterglow
  49. GRB 090912: Swift-XRT refined analysis
  50. GRB 090912, Swift-BAT refined analysis
  51. GRB 090912: Swift/UVOT Upper Limits
  52. GRB 090912 optical upper limit
  53. GRB 090912: Enhanced Swift-XRT position
  54. GRB 090912: Swift detection of a burst
  55. GRB 090910: Fermi GBM detection
  56. GRB 090814A: Skynet/DSO & GORT Observations
  57. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  58. GRB 090904B: GROND detection of the optical afterglow
  59. GRB 090831A: Suzaku WAM observation of the prompt emission
  60. GRB 090904B: Swift/UVOT Refined Analysis
  61. GRB 090902B: Suzaku WAM observation of the prompt emission
  62. GRB 090829A: Suzaku WAM observation of the prompt emission
  63. GRB 090904B: Fermi GBM detection
  64. GRB 090904A: Swift-XRT refined analysis
  65. GRB 090904B: Swift XRT Refined Analysis
  66. GRB 090904B: Swift-BAT refined analysis
  67. GRB 090902B: VLA radio detection
  68. GRB 090904A: Swift-BAT refined analysis
  69. GRB 090904B: Enhanced Swift-XRT position
  70. GRB 090904A: Enhanced Swift-XRT position
  71. GRB 090904A: NOT observations
  72. GRB090904B: REM observations
  73. GRB 090904B: Swift detection of a burst
  74. GRB 090904: Swift detection of a burst
  75. GRB 090902B: Swift/UVOT refined analysis
  76. GRB090902B: Swift XRT refined analysis
  77. GRB 090902B: Faulkes Telescope North observations
  78. GRB 090902B: GROND NIR Afterglow Observations
  79. GRB 090902B: Enhanced Swift-XRT position
  80. GRB 090902B: Optical afterglow candidate
  81. GRB090902B: Swift/UVOT observations
  82. GRB 090902B: Swift/XRT Afterglow Candidate
  83. GRB 090902B: Fermi LAT detection
  84. GRB 090902B: Fermi GBM detection of a bright burst
  85. GRB 090902: Fermi GBM detection
  86. GRB 090831A: IPN Triangulation
  87. GRB 090831C BAT refined analysis
  88. GRB 090831C: GROND upper limits
  89. Swift Trigger 361477, called GRB090831B, is probably not real.
  90. GRB090831C: Swift/UVOT upper limits
  91. GRB 090831B: MITSuME optical upper limits
  92. GRB 090831C: Swift XRT Refined Analysis
  93. GRB 090829B: Fermi GBM Detection
  94. GRB 090831C: Enhanced Swift-XRT position
  95. GRB 090831C: Swift detection of a burst
  96. GRB 090831B, RIMOTS optical upper limits
  97. GRB 090831: MAXI GSC detection
  98. GRB 090831B: Swift detection of a possible burst
  99. GRB 090831: Fermi GBM detection
  100. GRB090829: Fermi GBM Detection

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