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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

8490 results found.

  1. GRB 170306A: Swift detection of a burst
  2. LIGO/Virgo G275697: Liverpool Telescope classification of EM candidates
  3. Konus-Wind observation of GRB 170228A
  4. LIGO/Virgo G275697: Additional iPTF Optical Transient Candidates
  5. LIGO/Virgo G275404: Additional iPTF Optical Transient Candidates
  6. LIGO/Virgo G275697: iPTF Optical Transient Candidates
  7. LIGO/Virgo G275404: iPTF Optical Transient Candidates
  8. LIGO/Virgo G275404: Fermi GBM Upper Limits
  9. LIGO/Virgo G275404: A near-infrared transient in the error circle of AGL J1914+1043
  10. LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
  11. LIGO/Virgo G275697: REM optical/NIR observations
  12. LIGO/Virgo G275697: AGILE MCAL Observations
  13. LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
  14. LIGO/VIRGO G275697: Fermi GBM Observations
  15. LIGO/Virgo G275697 ANTARES search
  16. LIGO/Virgo G275697: IceCube neutrino observations
  17. LIGO/Virgo G275697: Identification of a GW CBC Candidate
  18. LIGO/Virgo G275404: Keck LRIS classification of MASTER PSN candidate
  19. LIGO/Virgo G275404: REM optical/NIR observations
  20. LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
  21. LIGO/Virgo G275404: INTEGRAL search for a prompt gamma-ray counterpart
  22. LIGO/Virgo G275404: AGILE-GRID detection of a possible gamma-ray transient
  23. LIGO/Virgo G275404 ANTARES search
  24. LIGO/Virgo G275404: AGILE-GRID preliminary analysis
  25. LIGO/Virgo G275404: Fermi GBM Observations
  26. LIGO/Virgo G275404: AGILE MCAL observations
  27. LIGO/Virgo G275404: IceCube neutrino observations
  28. LIGO/Virgo G275404: Identification of a GW CBC Candidate
  29. GRB 170222A: Swift-XRT observations
  30. LIGO/Virgo G274296: HAWC follow-up
  31. GRB 170222A: Tiled Swift observations
  32. GRB 170222A: Swift ToO observations
  33. LIGO/Virgo G274296: No change to estimate of LIGO false alarm probability
  34. Swift Trigger 739517 is probably not a GRB
  35. LIGO/Virgo G274296: iPTF Optical Transient Candidates
  36. LIGO/Virgo G274296: Kanata 1.5m optical spectroscopy of MASTER optical transient
  37. LIGO/Virgo G274296: Global MASTER Net PSN and QSO detection
  38. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  39. LIGO/Virgo G274296: IceCube neutrino observations
  40. LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
  41. LIGO/Virgo G274296: Fermi-LAT search for a high-energy gamma-ray counterpart
  42. LIGO/Virgo G274296: AstroSat CZTI upper limits
  43. LIGO/Virgo G274296 ANTARES search
  44. LIGO/Virgo G274296: CNEOST imaging coverage and an optical transient
  45. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  46. LIGO/Virgo G274296: Global MASTER Net two OTs detection
  47. LIGO/Virgo G274296: INTEGRAL search for a prompt gamma-ray counterpart
  48. LIGO/Virgo G274296: REM optical/NIR observations
  49. LIGO/VIRGO G274296: Fermi GBM Observations
  50. LIGO/Virgo G274296: Identification of a GW Burst Candidate
  51. Trigger 738728: Swift triggered on noise near NGC 4096
  52. GRB 170214A: NOT optical afterglow confirmation
  53. GRB 170209A: GROND confirmation of MASTER afterglow
  54. GRB 170214A: Swift ToO observations
  55. GRB 170209A: Swift ToO observations
  56. GRB 170208B WHT nIR candidate afterglow
  57. GRB 170208B: GROND observations
  58. GRB 170208B: Swift detection of a burst
  59. GRB 170208A: Swift detection of a burst
  60. LIGO/Virgo G270580: ANTARES upper limits
  61. GRB 170206B: Swift detection of a burst
  62. GRB 170205A: Swift detection of a burst with an optical counterpart
  63. GRB 170202A: Swift detection of a burst with an optical afterglow
  64. GRB 170131A: Fermi GBM observation
  65. GRB 170131A: Swift ToO observations
  66. LIGO/Virgo G268556: FLOYDS Spectrum of iPTF17cf/PS17fr Favors an AGN Classification
  67. GRB 170127C: Tiled Swift observations
  68. GRB 170127B: Swift detection of a short burst
  69. GRB 170127A: Swift detection of a burst
  70. GRB 170126A: Swift detection of a burst with an optical counterpart
  71. GRB 170115B: AGILE/SuperAGILE localisation
  72. LIGO/Virgo G270580: No change to estimate of LIGO false alarm probability
  73. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  74. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  75. LIGO/Virgo G268556: ANTARES upper limits
  76. GRB 170121B: AbAO optical observations
  77. GRB 170121B: Swift-XRT and UVOT observations
  78. GRB 170121B: Swift ToO observations
  79. LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
  80. LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
  81. LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
  82. LIGO/Virgo G270580 ANTARES search
  83. LIGO/Virgo G270580: Identification of a GW Burst Candidate
  84. GRB 170117A: Swift ToO observations
  85. GRB 170115B: Tiled Swift observations
  86. GRB 170115A: Swift detection of a burst
  87. GRB 170113A: Swift detection of a burst with an optical counterpart
  88. LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
  89. GRB 170112A: REM optical/NIR observations
  90. LIGO/Virgo G268556: Gemini spectra of Pan-STARRS1 transients
  91. GRB 170112A: Swift detection of a short burst
  92. LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
  93. LIGO/Virgo G268556/GW170104: Campo Imperatore Observatory observations
  94. GRB 170111A: Swift detection of a burst
  95. LIGO/Virgo G268556: Liverpool Telescope Spectroscopy of iPTF candidates
  96. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  97. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  98. LIGO/Virgo G268556: iPTF Optical Transient Candidates
  99. Swift Trigger 730874 is not astrophysical
  100. LIGO/Virgo G268556/GW170104: Asiago Observations

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