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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"

11546 results found.

  1. LIGO/Virgo S190521g: No candidate counterpart in Fermi-LAT observations
  2. LIGO/Virgo S190519bj: Fermi-LAT search for a high-energy gamma-ray counterpart
  3. Fermi GRB190520.6 Global MASTER-Net observations report
  4. GRB 190519A: AstroSat CZTI detection
  5. GRB 190519A: CALET Gamma-Ray Burst Monitor detection
  6. LIGO/Virgo S190519bj: Fermi GBM Observations
  7. GRB 190519A: Fermi GBM observation
  8. GRB 190519A: Fermi GBM Final Real-time Localization
  9. Fermi GRB190517.81 Global MASTER-Net observations report
  10. Fermi Trigger 579814215 / GRB 190517813 / GRB190517A: BALROG localization
  11. GRB 190517A: Fermi GBM Final Real-time Localization
  12. LIGO/Virgo S190517h: Fermi-LAT search for a high-energy gamma-ray counterpart
  13. LIGO/Virgo S190517h: Fermi GBM Observations
  14. GRB 190515A: CALET Gamma-Ray Burst Monitor detection
  15. Fermi GRB190517.1 Global MASTER-Net observations report
  16. Fermi GRB190515.49 Global MASTER-Net observations report
  17. GRB 190515A: Insight-HXMT/HE detection
  18. GRB 190515A: Fermi GBM detection
  19. GRB 190515A: Fermi-LAT detection
  20. Fermi GRB190515.43 Global MASTER-Net observations report
  21. GRB 190510A: CALET Gamma-Ray Burst Monitor detection
  22. GRB 190515A: Fermi GBM Final Real-time Localization
  23. Fermi GRB190514.67 Global MASTER-Net observations report
  24. LIGO/Virgo S190513bm: Fermi GBM Observations
  25. Konus-Wind observation of GRB 190511A
  26. LIGO/Virgo S190513bm: Fermi-LAT search for a high-energy gamma-ray counterpart
  27. LIGO/Virgo S190512at: Fermi-LAT search for a high-energy gamma-ray counterpart
  28. LIGO/Virgo S190512at: Fermi GBM Observations
  29. GRB 190512A: Fermi GBM observation
  30. Fermi GRB190512.62 Global MASTER-Net observations report
  31. Fermi GRB190512.61 Global MASTER-Net observations report
  32. GRB 190512A: Fermi GBM Final Real-time Localization
  33. IPN triangulation of GRB 190510A (short)
  34. GRB 190511A: NOT optical afterglow
  35. GRB 190511A: Fermi-LAT detection
  36. GRB 190511A: Fermi GBM observation
  37. LIGO/Virgo S190510g: DESGW counterpart candidates over 80% of the GW localization area
  38. GRB 190511A: Fermi GBM Final Real-time Localization
  39. LIGO/Virgo S190510g: Fermi-LAT search for a high-energy gamma-ray counterpart
  40. GRB 190510A: Fermi GBM Final Real-time Localization
  41. Fermi GRB190510.12 Global MASTER-Net observations report
  42. LIGO/Virgo S190510g: Fermi GBM Observations
  43. GRB 190508A: GOTO optical search - no counterparts
  44. GRB 190508B: Fermi GBM Final Real-time Localization
  45. Fermi GRB190508.81 Global MASTER-Net observations report
  46. GRB 190508A: Fermi GBM Final Real-time Localization
  47. Fermi GRB190507.71 Global MASTER-Net observations report
  48. GRB 190507B: GOTO optical counterpart search
  49. Fermi GRB190508.11 Global MASTER-Net observations report
  50. Fermi GRB190507.97 Global MASTER-Net observations report
  51. GRB 190507B: Fermi GBM Final Real-time Localization
  52. Fermi GRB190507.27 Global MASTER-Net observations report
  53. IceCube-190504A: MASTER optical monitoring analysis
  54. Fermi Trigger 578903308 / GRB 190507270 / GRB190507A: BALROG localization
  55. GRB 190507A: Fermi GBM Final Real-time Localization
  56. Fermi GRB190506.58 Global MASTER-Net observations report
  57. Update to the Fermi GBM GCN Reporting
  58. IceCube-190504A: Swift-XRT Follow-up Observations
  59. Fermi GRB190505.82 Global MASTER-Net observations report
  60. Fermi-LAT Gamma-ray Observations of IceCube-190504A
  61. Fermi GRB190505.05 Global MASTER-Net observations report
  62. Fermi GRB190504.68 Global MASTER-Net observations report
  63. IPN triangulation of GRB 190504A (short)
  64. LIGO/Virgo S190503bf: Fermi-LAT search for a high-energy gamma-ray counterpart
  65. Fermi-LAT Gamma-ray Observations of IceCube-190503A
  66. LIGO/Virgo S190503bf: Fermi-GBM Observations
  67. Fermi-GBM Observations of IceCube-190503A
  68. IceCube-190503A - IceCube observation of a high-energy neutrino candidate event
  69. IPN Triangulation of GRB 190501A (long/bright)
  70. Fermi Trigger 578462495 / GRB 190502168 / GRB190502A: BALROG localization
  71. Fermi GRB190501.79 Global MASTER-Net observations report
  72. Fermi GRB190429.74 Global MASTER-Net observations report
  73. LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
  74. GRB 190427A: CALET Gamma-Ray Burst Monitor detection
  75. Fermi Trigger 578170097 / GRB 190428783 / GRB190428A: BALROG localization
  76. GRB 190419A: AstroSat CZTI detection
  77. Fermi GRB190427.19 Global MASTER-Net observations report
  78. GRB 190427A: Fermi GBM detection
  79. LIGO/Virgo S190425z: Fermi-LAT search for a high-energy gamma-ray counterpart
  80. LIGO/Virgo S190426c: Fermi GBM Observations
  81. LIGO/Virgo S190425z: Candidates from the Zwicky Transient Facility
  82. LIGO/Virgo S190425z: Fermi GBM Observations
  83. LIGO/Virgo S190425z: INTEGRAL IBIS prompt observation
  84. LIGO/Virgo S190421ar: Fermi-LAT search for a high-energy gamma-ray counterpart
  85. Fermi GRB190425.09 Global MASTER-Net observations report
  86. GRB 190422A: Fermi GBM detection
  87. Fermi GRB190422.96 Global MASTER-Net observations report
  88. Fermi GRB190422.67 Global MASTER-Net observations report
  89. LIGO/Virgo S190421ar: Fermi-GBM Observations
  90. Fermi GRB190420.98 Global MASTER-Net observations report
  91. Fermi GRB190419.41 Global MASTER-Net observations report
  92. Fermi trigger 576241792 / GRB 190406B: MASTER optical observation
  93. Fermi Trigger 577360542 / GRB 190419414 / GRB190419A: BALROG localization
  94. Fermi GRB190418.92 Global MASTER-Net observations report
  95. GRB 190406B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 576241792)
  96. IPN Triangulation of GRB 190415A
  97. Fermi GRB190417.46 Global MASTER-Net observations report
  98. GRB 190415A: Insight-HXMT/HE detection
  99. Fermi Trigger 576994194 / GRB 190415173 / : BALROG localization
  100. Fermi GRB190415.17 Global MASTER-Net observations report

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