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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 081024B: Swift-XRT observations
  2. GRB 081025: Burst detection from Swift-BAT slew data
  3. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  4. Fermi-LAT observation of GRB 081024B
  5. Swift UVOT observations of GRB 081024
  6. GRB 081024: Swift-XRT refined analysis
  7. GRB 081024, Swift-BAT refined analysis
  8. GRB 081024: Enhanced Swift-XRT position
  9. GRB 081024: Faulkes Telescope North optical observations
  10. GRB 081024: KAIT Optical Limits
  11. GRB 081024: Early Super-LOTIS Observations
  12. GRB 081024A: ROTSE-III Optical Limits
  13. GRB 081024: Swift detection of a burst
  14. GRB 081022, Swift-BAT refined analysis
  15. GRB 081016A: Swift-XRT refined analysis
  16. GRB 081022: Swift detection of a burst
  17. GRB 081012: Swift-XRT Refined Analysis
  18. Swift trigger 332287 is not a GRB
  19. Swift detection of a possible burst (trigger 332287)
  20. GRB 081012 - Enhanced Swift XRT position
  21. GRB 081017, Swift-BAT refined analysis
  22. GRB 081017: REM early observations
  23. GRB 081017: Swift detection of a burst
  24. GRB 081016B, Swift-BAT refined analysis
  25. GRB 081016B: Swift/UVOT Upper Limits
  26. GRB 081011: Swift XRT refined analysis
  27. GRB 081016B: Swift-XRT Team refined Analysis
  28. GRB 081016B: Enhanced Swift-XRT position
  29. GRB 081016B: ROTSE-III Optical Limits
  30. GRB 081016B: Swift detection of a burst
  31. GRB 081011: Enhanced Swift-XRT position
  32. GRB 081016: Swift-XRT candidate afterglow detection
  33. Swift detection of flare on CC Eri
  34. GRB 081016: A long GRB discovered by INTEGRAL
  35. Trigger 331721 Due to Swift startracker loss-of-lock
  36. Detection of flare star Algol in Swift-BAT slew data
  37. GRB 081009: Fermi GBM detection
  38. GRB 081012: GROND upper limits
  39. GRB 081008: Galaxy associated with z=1.967 absorber
  40. Swift-BAT triggered on the flare star Algol
  41. GRB 081012: Fermi GBM detection
  42. GRB 081007 and GRB 081007B: Fermi GBM detection
  43. GRB 080430: optical observations
  44. GRB 081008 optical upper limit
  45. GRB 081012: Observations from NOT
  46. GRB 081012: Swift/UVOT analysis of initial observations
  47. GRB 081012: Swift/XRT detection
  48. GRB 081012, Swift-BAT refined analysis
  49. GRB 081012: ROTSE-III Optical Limits
  50. GRB 081012: Swift detection of a burst
  51. Revised table for GRB 081011 UVOT detections
  52. GRB081011: UVOT detection of an optical afterglow
  53. GRB 081011: Swift/XRT detection
  54. GRB 081011, Swift-BAT refined analysis
  55. GRB 081008, SMARTS optical/IR afterglow observations
  56. GRB 081011: Swift detection of a burst
  57. GRB 081007: Radio Detection
  58. Konus-Wind observation of GRB 081001
  59. GRB 081007: Rapid PROMPT Detections
  60. GRB 081008, Swift-BAT refined analysis
  61. GRB 081008: VLT redshift confirmation
  62. GRB 081008: Swift-XRT Refined Analysis
  63. GRB081008: Swift/UVOT observations
  64. GRB 081008: Enhanced Swift-XRT position
  65. GRB 081008: Gemini-South Absorption Redshiftt
  66. GRB 081008: VLT/FORS2 spectroscopy
  67. GRB 081008: Swift detection of a burst with optical afterglow
  68. GRB 081008: ROTSE-III Detection of Optical Counterpart
  69. GRB081006B: Fermi GBM detection
  70. GRB081006: Fermi GBM detection
  71. GRB081007: Swift/UVOT Observations
  72. GRB 081007, SMARTS optical afterglow observations
  73. GRB 081007, Swift-BAT refined analysis
  74. GRB 081007: Early RAPTOR measurements of optical counterpart
  75. GRB 081007: Swift-XRT Team refined analysis
  76. GRB 081007: Gemini-south redshift
  77. GRB 081007: Enhanced Swift-XRT position
  78. GRB 081007, Faulkes Telescope North optical observations
  79. GRB 081007, SMARTS optical/IR afterglow observations
  80. GRB 081007: REM NIR and optical counterpart
  81. GRB 081007: Swift detection of a burst with optical afterglow
  82. GRB081003C: GLAST Burst Monitor detection
  83. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  84. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  85. GRB 081003B: TAROT Calern observatory optical observations
  86. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  87. GRB 081003B: Swift-XRT upper limit
  88. GRB 081003A: OSN optical observations
  89. GRB 081001: Further observations from OSN
  90. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  91. GRB081003B: Optical limits from Spain
  92. GRB 081003A: Swift-XRT Team position and analysis
  93. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  94. GRB 081003B: a long GRB detected with INTEGRAL
  95. GRB 080928: Fermi GBM detection
  96. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  97. GRB 081003: A long GRB discovered by INTEGRAL
  98. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  99. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  100. Trigger 330353: Swift detection of a Galactic short soft burst

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