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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"

346 results found.

  1. Fermi GRB 251115A: Global MASTER-Net observations report
  2. Fermi trigger No 784717756: Global MASTER-Net observations report
  3. Fermi GRB 251114A: Global MASTER-Net observations report
  4. GRB 251013C: BOOTES-6 early optical detection
  5. Fermi GRB 251013A: Global MASTER-Net observations report
  6. GRB 251010A: AstroSat CZTI detection
  7. GRB 251006A: Fermi GBM Observation
  8. Fermi GRB 250919A: Global MASTER-Net observations report
  9. Fermi GRB 250909A: Global MASTER-Net observations report
  10. GRB 250625A: SVOM/C-GFT upper limit in early phase
  11. Fermi trigger No 771718064: Global MASTER-Net observations report
  12. Fermi trigger No 770867684: Global MASTER-Net observations report
  13. Swift GRB250603.05: Global MASTER-Net observations report
  14. Fermi GRB 250214A: Global MASTER-Net observations report
  15. Fermi GRB 241206A: Global MASTER-Net observations report
  16. Fermi GRB 241104A: Global MASTER-Net observations report
  17. EP240918a: EP observation update
  18. Fermi GRB 240828A: Global MASTER-Net observations report
  19. Fermi trigger No 746438824: Global MASTER-Net observations report
  20. Fermi GRB 240814C: Global MASTER-Net observations report
  21. Fermi trigger No 745306088: Global MASTER-Net observations report
  22. Fermi trigger No 740949590: Global MASTER-Net observations report
  23. Fermi GRB 240610A: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  25. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  26. GRB 240418A: Swift detection of a burst
  27. GRB 240329A: AstroSat CZTI detection
  28. IceCube Alert 240229.66: Global MASTER-Net observations report
  29. Fermi GRB 240213A: Global MASTER-Net observations report
  30. GRB 240102C: AstroSat CZTI detection
  31. Fermi trigger No 725806648: Global MASTER-Net observations report
  32. Fermi trigger No 724781422: Global MASTER-Net observations report
  33. Swift GRB231215.41: Global MASTER-Net observations report
  34. Fermi trigger No 723581802: Global MASTER-Net observations report
  35. IceCube Alert 231103.39: Global MASTER-Net observations report
  36. Fermi GRB 231030B: Global MASTER-Net observations report
  37. Fermi GRB 230827A: Global MASTER-Net observations report
  38. GRB 230824B: AstroSat CZTI detection
  39. Fermi GRB 230818A: Global MASTER-Net observations report
  40. Fermi trigger No 712713532: Global MASTER-Net observations report
  41. IceCube Alert 230724.08: Global MASTER-Net observations report
  42. Fermi GRB 230723A: Global MASTER-Net observations report
  43. Fermi GRB 230707A: Global MASTER-Net observations report
  44. Swift GRB 230622A: Global MASTER-Net observations report
  45. LIGO/Virgo S230601bf: Global MASTER-Net observations report
  46. GRB 230217A: ATCA rapid-response radio detection
  47. Fermi GRB 221215B: Global MASTER-Net observations report
  48. IceCube Alert 221124.66: Global MASTER-Net observations report
  49. Integral GRB221010.89: Global MASTER-Net observations report
  50. Konus-Wind detection of GRB 221009A
  51. GRB 220907A: Fermi GBM observation
  52. Konus-Wind detection of GRB 220609B
  53. Fermi trigger No 675411172: Global MASTER-Net observations report
  54. IceCube Alert 220513.97: Global MASTER-Net observations report
  55. GRB 220426A: Swift-XRT and UVOT observations
  56. Fermi GRB 220411A: Global MASTER-Net observations report
  57. GRB 220315A: MASTER Global Robotic Net optical observations
  58. Fermi GRB 220310B: Global MASTER-Net observations report
  59. Fermi GRB 220211A: Global MASTER-Net observations report
  60. GRB 220101A: Swift-BAT refined analysis
  61. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  62. GRB 211221A: Swift detection of a burst
  63. Fermi GRB 211204C: Global MASTER-Net observations report
  64. Fermi trigger No 658971499: Global MASTER-Net observations report
  65. GRB 211110A: AstroSat CZTI detection
  66. Fermi trigger No 652927551: Global MASTER-Net observations report
  67. GRB 210807C: Fermi GBM detection
  68. Swift GRB210807.79: Global MASTER-Net observations report
  69. Fermi trigger No 649390368: Global MASTER-Net observations report
  70. GRB 210730A: Fermi GBM observation
  71. Fermi trigger No 647942198: Global MASTER-Net observations report
  72. Fermi GRB 210709A: Global MASTER-Net observations report
  73. Integral GRB210707.02: Global MASTER-Net observations report
  74. Fermi GRB 210627B: Global MASTER-Net observations report
  75. Fermi trigger No 645047470: Global MASTER-Net observations report
  76. Swift GRB 210610B: Global MASTER-Net observations report
  77. GRB 210528B: MAXI/GSC detection
  78. Fermi GRB 210503A: Global MASTER-Net observations report
  79. GRB 210226A: Fermi GBM detection
  80. GRB 210218A: Swift/UVOT observations
  81. GRB 210218A: Swift-XRT observations
  82. Konus-Wind detection of GRB 210124B
  83. Swift GRB 201221A: Global MASTER-Net observations report
  84. Fermi GRB 201121A: Global MASTER-Net observations report
  85. GRB 201026A: Swift-BAT refined analysis
  86. Konus-Wind observation of GRB 200914A
  87. LAT GRB200803.15: Global MASTER-Net observations report
  88. Fermi GRB 200803A: Global MASTER-Net observations report
  89. GRB 200711A: Swift/UVOT Upper Limits
  90. Fermi GRB 200616A: Global MASTER-Net observations report
  91. Fermi GRB 200605A: Global MASTER-Net observations report
  92. Konus-Wind detection of short/hard GRB 200521A
  93. GRB 200514B: BALROG localization (Fermi Trigger 611140062 / GRB 200514380)
  94. bright SGR burst detected by CALET Gamma-Ray Burst Monitor
  95. IceCube Alert 200410.97: Global MASTER-Net observations report
  96. Fermi trigger No 606263732: Global MASTER-Net observations report
  97. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  98. Swift GRB200205.81: Global MASTER-Net observations report
  99. Fermi trigger No 601841483: Global MASTER-Net observations report
  100. GRB 200125A: Swift-BAT refined analysis

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