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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 170202A: 15 GHz upper limits from AMI
  2. GRB 170210A: POLAR observation
  3. GRB 170208C: POLAR Observation
  4. IBAS Trigger 7691 is not a GRB
  5. GRB 170209A: Swift-XRT observations
  6. IPN Triangulation of GRB 170210A
  7. GRB 170210A: Fermi GBM observation
  8. Konus-Wind observation of GRB 170209A
  9. GRB 170209A: Swift ToO observations
  10. GRB 170208B: Swift/UVOT Upper Limits
  11. IPN Triangulation of GRB 170209A
  12. GRB 170208B: RATIR Optical and NIR Observations
  13. GRB 170208B: Swift-BAT refined analysis
  14. GRB 170208A: Swift-BAT refined analysis
  15. GRB 170209A: Fermi GBM Detection
  16. Correction to GCN 20640: GRB 170208B: GROND observations
  17. Fermi Trigger 508295323: MASTER-OAFA possible OT detection
  18. GRB 170208A: Swift-XRT refined Analysis
  19. LIGO/Virgo G270580: AstroSat CZTI upper limits
  20. GRB 170208B WHT nIR candidate afterglow
  21. GRB 170208B: Fermi GBM Detection
  22. GRB 170207A: POLAR Observation
  23. GRB 170208A: Swift/UVOT Upper Limits
  24. Konus-Wind observation of GRB 170208B
  25. GRB 170207A: AstroSat CZTI detection
  26. Konus-Wind observation of GRB 170208A
  27. GRB 170208B: GROND observations
  28. GRB 170206C: POLAR Observation
  29. GRB 170208B: NOT upper limits
  30. GRB 170208B: Swift-XRT refined Analysis
  31. GRB 170208B: Etelman observatory optical observations
  32. GRB 170208B: Enhanced Swift-XRT position
  33. GRB 170208A: Enhanced Swift-XRT position
  34. GRB 170208A: Fermi GBM Detection
  35. GRB 170208B: Swift detection of a burst
  36. GRB 170208A: Swift detection of a burst
  37. GRB 170207A: Fermi GBM observation
  38. Konus-Wind observation of GRB 170207A
  39. IPN Triangulation of GRB 170207A (long/very bright)
  40. LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
  41. GRB 170206B: Swift/UVOT Upper Limits
  42. Konus-Wind observation of GRB 170206A
  43. GRB 170206A: POLAR observation
  44. IPN Triangulation of GRB 170206A (short/hard)
  45. GRB 170206B: Swift-BAT refined analysis
  46. LIGO/Virgo G270580: ANTARES upper limits
  47. GRB 170206B: Swift-XRT refined Analysis
  48. GRB 170206B: Enhanced Swift-XRT position
  49. GRB 170206B: Swift detection of a burst
  50. GRB 170206A: Fermi-LAT detection
  51. GRB 170206A: Fermi GBM observation
  52. GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
  53. Konus-Wind observation of GRB 170205A
  54. GRB 170205A: Swift-BAT refined analysis
  55. GRB 170205A: NOT afterglow observations
  56. GRB 170205A: Swift-XRT refined Analysis
  57. GRB 170205A: Enhanced Swift-XRT position
  58. GRB 170205A: RATIR Optical and NIR Observations
  59. Fermi GBM trigger 508010837/170205755 is not a GRB
  60. Fermi GBM trigger 507959893/170205165 is not a GRB
  61. GRB 170202A: SMARTS optical/IR afterglow observations
  62. GRB 170205A: LCO FTN observations
  63. Konus-Wind observation of GRB 170202A
  64. GRB 170205A: Swift detection of a burst with an optical counterpart
  65. GRB 170202B POLAR Observation
  66. GRB 170202A: SQUEAN Observation (2nd night)
  67. GRB 170131A: POLAR Observation
  68. GRB 170202A: Zadko observatory - Gingin optical observations
  69. GRB 170202A: Etelman Observatory optical observations
  70. GRB 170203A: Swift-BAT refined analysis
  71. GRB 170202A: Swift-BAT refined analysis
  72. GRB 170202A: RATIR Optical and NIR Observations
  73. GRB 170202A: SQUEAN Observation
  74. GRB 170202A: LCO FTN observations
  75. GRB 170202A: Swift-XRT refined Analysis
  76. GRB 170202A: T100 observations
  77. GRB 170202A VLT/X-shooter redshift [minor correction]
  78. GRB 170202A: Xinglong 2.16m photometry and spectroscopic redshift
  79. GRB 170202A: Swift/UVOT Detection
  80. GRB 170202A: Enhanced Swift-XRT position
  81. GRB 170202A: MITSuME Akeno Optical Observation
  82. GRB 170202A: Redshift from OSIRIS/GTC
  83. GRB 170203A: Swift detection of a burst
  84. GRB 170202A: NOT afterglow observations
  85. GRB 170202A: Kanata optical and infrared observations
  86. GRB 170202A: Zadko observatory - Gingin optical observations
  87. GRB 170202A: LCO Sutherland observations
  88. GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
  89. GRB 170202A: Mini-MegaTORTORA upper limits
  90. GRB 170202A : Xinglong TNT optical observation
  91. GRB 170202A: Swift detection of a burst with an optical afterglow
  92. GRB 170131A: Swift/UVOT Upper Limits
  93. GRB 170131A: Swift-XRT observations
  94. GRB 170131A: Fermi GBM observation
  95. GRB 170131A: Swift ToO observations
  96. GRB 170131A detected in Swift/BAT ground processing
  97. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  98. GRB 170130A: POLAR Observation
  99. Konus-Wind observation of GRB 170127C (short/hard GRB with extended emission)
  100. GRB 170127B: Swift-BAT refined analysis

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