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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"
  1. GRB 081028: optical observations at the NOT
  2. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  3. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  4. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  5. GRB 081028: Swift detection of a burst
  6. GRB 081025: TLS upper limits
  7. GRB 081024: No radio detection with the VLA
  8. GRB081025: RTT150 optical observations
  9. GRB081024B: P200 Observations
  10. GRB 081024B: Swift-XRT further observations
  11. GRB 081025 BAT refined analysis
  12. Swift UVOT observations of GRB081025
  13. Swift UVOT observations of GRB081024B
  14. Konus-Wind observation of GRB 081025
  15. GRB 081025: Swift-XRT position
  16. GRB 081024B: Swift-XRT observations
  17. GRB 081025: Burst detection from Swift-BAT slew data
  18. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  19. Fermi-LAT observation of GRB 081024B
  20. Swift UVOT observations of GRB 081024
  21. GRB 081024: Swift-XRT refined analysis
  22. GRB 081024, Swift-BAT refined analysis
  23. GRB 081024: Enhanced Swift-XRT position
  24. GRB 081024: Faulkes Telescope North optical observations
  25. GRB 081024: KAIT Optical Limits
  26. GRB 081024: Early Super-LOTIS Observations
  27. GRB 081024A: ROTSE-III Optical Limits
  28. GRB 081024: Swift detection of a burst
  29. GRB 081022, Swift-BAT refined analysis
  30. GRB 081016A: Swift-XRT refined analysis
  31. GRB 081022: Swift detection of a burst
  32. GRB 081012: Swift-XRT Refined Analysis
  33. Swift trigger 332287 is not a GRB
  34. Swift detection of a possible burst (trigger 332287)
  35. GRB 081012 - Enhanced Swift XRT position
  36. GRB 081017, Swift-BAT refined analysis
  37. GRB 081017: REM early observations
  38. GRB 081017: Swift detection of a burst
  39. GRB 081016B, Swift-BAT refined analysis
  40. GRB 081016B: Swift/UVOT Upper Limits
  41. GRB 081011: Swift XRT refined analysis
  42. GRB 081016B: Swift-XRT Team refined Analysis
  43. GRB 081016B: Enhanced Swift-XRT position
  44. GRB 081016B: ROTSE-III Optical Limits
  45. GRB 081016B: Swift detection of a burst
  46. GRB 081011: Enhanced Swift-XRT position
  47. GRB 081016: Swift-XRT candidate afterglow detection
  48. Swift detection of flare on CC Eri
  49. GRB 081016: A long GRB discovered by INTEGRAL
  50. Trigger 331721 Due to Swift startracker loss-of-lock
  51. Detection of flare star Algol in Swift-BAT slew data
  52. GRB 081009: Fermi GBM detection
  53. GRB 081012: GROND upper limits
  54. GRB 081008: Galaxy associated with z=1.967 absorber
  55. Swift-BAT triggered on the flare star Algol
  56. GRB 081012: Fermi GBM detection
  57. GRB 081007 and GRB 081007B: Fermi GBM detection
  58. GRB 080430: optical observations
  59. GRB 081008 optical upper limit
  60. GRB 081012: Observations from NOT
  61. GRB 081012: Swift/UVOT analysis of initial observations
  62. GRB 081012: Swift/XRT detection
  63. GRB 081012, Swift-BAT refined analysis
  64. GRB 081012: ROTSE-III Optical Limits
  65. GRB 081012: Swift detection of a burst
  66. Revised table for GRB 081011 UVOT detections
  67. GRB081011: UVOT detection of an optical afterglow
  68. GRB 081011: Swift/XRT detection
  69. GRB 081011, Swift-BAT refined analysis
  70. GRB 081008, SMARTS optical/IR afterglow observations
  71. GRB 081011: Swift detection of a burst
  72. GRB 081007: Radio Detection
  73. Konus-Wind observation of GRB 081001
  74. GRB 081007: Rapid PROMPT Detections
  75. GRB 081008, Swift-BAT refined analysis
  76. GRB 081008: VLT redshift confirmation
  77. GRB 081008: Swift-XRT Refined Analysis
  78. GRB081008: Swift/UVOT observations
  79. GRB 081008: Enhanced Swift-XRT position
  80. GRB 081008: Gemini-South Absorption Redshiftt
  81. GRB 081008: VLT/FORS2 spectroscopy
  82. GRB 081008: Swift detection of a burst with optical afterglow
  83. GRB 081008: ROTSE-III Detection of Optical Counterpart
  84. GRB081006B: Fermi GBM detection
  85. GRB081006: Fermi GBM detection
  86. GRB081007: Swift/UVOT Observations
  87. GRB 081007, SMARTS optical afterglow observations
  88. GRB 081007, Swift-BAT refined analysis
  89. GRB 081007: Early RAPTOR measurements of optical counterpart
  90. GRB 081007: Swift-XRT Team refined analysis
  91. GRB 081007: Gemini-south redshift
  92. GRB 081007: Enhanced Swift-XRT position
  93. GRB 081007, Faulkes Telescope North optical observations
  94. GRB 081007, SMARTS optical/IR afterglow observations
  95. GRB 081007: REM NIR and optical counterpart
  96. GRB 081007: Swift detection of a burst with optical afterglow
  97. GRB081003C: GLAST Burst Monitor detection
  98. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  99. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  100. GRB 081003B: TAROT Calern observatory optical observations

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