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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"

18435 results found.

  1. GRB 090929B: Suzaku WAM observation of the prompt emission
  2. GRB 091003: Swift-XRT confirmation of fading afterglow
  3. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  4. GRB 091003: UVOT-enhanced XRT position
  5. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  6. GRB 091003: Swift XRT analysis
  7. GRB 091003A: Fermi LAT detection
  8. GRB 090929A: Swift/UVOT Observations
  9. GRB 090929A, Swift-BAT refined analysis
  10. GRB 090929B, Swift-BAT refined analysis
  11. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  12. GRB 090929A: Swift-XRT non-detection
  13. Konus-Wind observation of GRB 090929A
  14. Konus-Wind observation of GRB 090929B
  15. GRB 090927: Fermi GBM observation
  16. GRB 090929B: Swift-XRT refined analysis
  17. GRB 090929B: Skynet/DSO Observations
  18. GRB 090929B: Swift/UVOT Observations
  19. Konus-RF observation of GRB 090929A
  20. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  21. GRB 090929A BAT location of the Fermi GBM burst
  22. Correction: GRB 090929B: Enhanced Swift-XRT position
  23. GRB 090929: Enhanced Swift-XRT position
  24. GRB 090929B: Swift detection of a burst
  25. GRB090926A: Swift-XRT refined analysis
  26. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  27. GRB 090926B: Fermi GBM detection
  28. GRB 090927: Zadko Telescope observations
  29. GRB 090927, Swift-BAT refined analysis of the possibly short burst
  30. Swift/UVOT observations of GRB 090927
  31. GRB 090927: Swift XRT refined analysis
  32. GRB 090927: Enhanced Swift-XRT position
  33. GRB090926B: Swift/UVOT Upper Limits
  34. GRB090926A: Swift/UVOT observations
  35. GRB 090927: Swift/UVOT detection of an optical afterglow
  36. GRB 090927: Swift detection of a short burst
  37. GRB 090926B: MAXI GSC detection
  38. GRB 090926B: Swift XRT refined analysis
  39. GRB 090926B: Swift-BAT refined analysis
  40. GRB 090926A: Swift/UVOT detection of an optical afterglow
  41. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  42. GRB090926A: UVOT-enhanced XRT position
  43. GRB 090926B: Swift detection of a burst
  44. GRB 090926: Fermi LAT detection
  45. GRB090904B : IRSF NIR upper limit
  46. Swift returns to normal operations
  47. GRB 090715B: Skynet/PROMPT Detections
  48. GRB 090916: Swift-XRT upper limit
  49. GRB 090807: Skynet/DSO Observations
  50. Swift-BAT temporarily off-line for a few days
  51. Short-Duration GRB 090916: Skynet/PROMPT Observations
  52. GRB 090912: optical observation
  53. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  54. GRB 090916, Swift-BAT refined analysis
  55. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  56. GRB 090916: Swift detection of a short burst
  57. GRB 090915 Swift-BAT detection of a burst in ground analysis
  58. GRB 090827: Confirmation of the X-ray afterglow
  59. GRB 090912: Swift-XRT refined analysis
  60. GRB 090912, Swift-BAT refined analysis
  61. GRB 090912: Swift/UVOT Upper Limits
  62. GRB 090912: Enhanced Swift-XRT position
  63. GRB 090912: Swift detection of a burst
  64. GRB 090814A: Skynet/DSO & GORT Observations
  65. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  66. GRB 090904B: GROND detection of the optical afterglow
  67. GRB 090904A: Swift/UVOT Refined Analysis
  68. GRB 090904B: Swift/UVOT Refined Analysis
  69. GRB 090904B: Fermi GBM detection
  70. GRB 090904A: Swift-XRT refined analysis
  71. GRB 090904B: Swift XRT Refined Analysis
  72. GRB 090904B: MOA-II Optical observation
  73. GRB 090904A: Enhanced Swift XRT position
  74. GRB 090904B: Swift-BAT refined analysis
  75. GRB 090904A: Swift-BAT refined analysis
  76. GRB 090904B: Enhanced Swift-XRT position
  77. GRB090904A: Correction to enhanced XRT position
  78. GRB 090904A: Enhanced Swift-XRT position
  79. GRB090904B: REM observations
  80. GRB 090904B: Swift detection of a burst
  81. GRB 090904A: ROTSE-III Optical Limits
  82. GRB 090904: Swift detection of a burst
  83. GRB 090902B: Swift/UVOT refined analysis
  84. GRB090902B: Swift XRT refined analysis
  85. GRB 090902B: Faulkes Telescope North observations
  86. GRB 090902B: GROND NIR Afterglow Observations
  87. GRB 090902B: Gemini-N absorption redshift
  88. GRB 090902B: Enhanced Swift-XRT position
  89. GRB 090902B: Optical afterglow candidate
  90. GRB090902B: Swift/UVOT observations
  91. GRB 090902B: Swift/XRT Afterglow Candidate
  92. GRB 090902B: Fermi LAT detection
  93. GRB 090831C BAT refined analysis
  94. GRB 090831C: GROND upper limits
  95. Swift Trigger 361477, called GRB090831B, is probably not real.
  96. GRB090831C: Swift/UVOT upper limits
  97. GRB 090831C: Swift XRT Refined Analysis
  98. GRB 090831C: Enhanced Swift-XRT position
  99. GRB 090831C: Swift detection of a burst
  100. GRB 090831B, RIMOTS optical upper limits

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