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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"

33608 results found.

  1. GRB 220521A: Swift detection of a burst
  2. GRB 220521A: Fermi GBM Final Real-time Localization
  3. Konus-Wind detection of GRB 220519A
  4. IPN triangulation of GRB 220519A
  5. GRB 220514A: AstroSat CZTI detection
  6. GRB 220518A: Swift-BAT refined analysis
  7. GRB 220518A: Swift-XRT refined Analysis
  8. Fermi GRB 220518B: Global MASTER-Net observations report
  9. GRB 220518B: Fermi GBM Final Real-time Localization
  10. GRB 220518A: Swift/UVOT Detection
  11. GRB 220518A: Enhanced Swift-XRT position
  12. Swift GRB 220518A: Global MASTER-Net observations report
  13. GRB 220518A: Swift detection of a burst
  14. GRB 220514A: MITSuME Akeno optical observation
  15. GRB 220514A: GRANDMA Optical Afterglow Observations
  16. Konus-Wind detection of GRB 220506A
  17. Konus-Wind detection of GRB 220514B
  18. GRB 220514A: Fermi GBM observation
  19. GRB 220514B: Swift-XRT observations
  20. GRB 220511A: Swift-XRT afterglow detection
  21. GRB 220514A: KAIT Optical Afterglow Confirmation
  22. GRB 220514B: Tiled Swift observations
  23. GRB 220514B: MAXI/GSC detection
  24. GRB 220514A: MeerLICHT optical afterglow candidate
  25. Fermi GRB 220514A: Global MASTER-Net observations report
  26. GRB 220514A: a long GRB detected by INTEGRAL
  27. GRB 220514A: BALROG localization (Fermi Trigger 674223877 / GRB 220514517)
  28. GRB 220514A: Fermi GBM Final Real-time Localization
  29. Fermi GRB 220513A: Global MASTER-Net observations report
  30. GRB 220513A: Fermi GBM Final Real-time Localization
  31. Konus-Wind detection of GRB 220511A
  32. GRB 220427A: MeerLICHT afterglow observations
  33. GRB 220511A: Fermi GBM observation
  34. GRB 220511A: Swift-XRT observations
  35. GRB 220511A: AstroSat CZTI detection
  36. GRB 220511A: BOOTES-2/TELMA optical upper limit
  37. Fermi GRB 220512A: Global MASTER-Net observations report
  38. GRB 220512A: Fermi GBM Final Real-time Localization
  39. GRB 220511A: Swift ToO observations
  40. GRB 220511A: Swift/BAT-GUANO arcminute localization
  41. Fermi GRB 220511A: Global MASTER-Net observations report
  42. GRB 220511A: AGILE detection
  43. GRB 220511A: BALROG localization (Fermi Trigger 673969321/ GRB 220511571)
  44. GRB 220511A: Fermi GBM Final Real-time Localization
  45. GRB 220507A: AstroSat CZTI detection
  46. GRB 220506A: MITSuME Akeno optical upper limits
  47. GRB 220506A: GIT optical upper limit.
  48. GRB 220508A: Fermi GBM Final Real-time Localization
  49. GRB 220507A: Fermi GBM Final Localization
  50. GRB 220506A: BOOTES-5/JGT optical upper limit
  51. GRB 220506A: Swift-XRT afterglow detection
  52. GRB 220506A: Tiled Swift observations
  53. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  54. GRB 220430A: Nanshan/NEXT optical upper limit
  55. GRB 220430A: Nanshan/HMT optical upper limit
  56. GRB 220430A: GIT optical upper limits
  57. IPN triangulation of GRB 220423A
  58. GRB 220427A: LCO Optical Observations
  59. GRB 220501A: Swift-BAT refined analysis
  60. GRB 220427A: GRANDMA Early Optical Afterglow Detection
  61. GRB 220501A: BOOTES-1 optical upper limit
  62. GRB 220501A: Fermi GBM observation
  63. GRB 220430A: AstroSat CZTI detection
  64. GRB 220501A: GRANDMA/TJML Optical Observations
  65. GRB 220501A: Fermi GBM Final Real-time Localization
  66. GRB 220501A: Swift detection of a burst
  67. GRB 220430A: Swift-BAT refined analysis
  68. GRB 220430A: CAHA 2.2m telescope optical limit
  69. GRB 220430A: Swift-XRT refined Analysis
  70. Swift GRB 220430A: Global MASTER-Net observations report
  71. GRB 220430A: GRANDMA observations
  72. GRB 220430A: Mondy and AbAO optical upper limits
  73. GRB 220430A: AGILE detection
  74. GRB 220430A: MeerLICHT optical upper limits
  75. GRB 220430A: Enhanced Swift-XRT position
  76. GRB 220430A: Swift detection of a burst or Swift J0630.4+0932
  77. GRB 220427A: Swift-BAT refined analysis
  78. GRB 220427A: VLT/X-shooter photometry
  79. GRB 220426A: Swift-XRT and UVOT observations
  80. GRB 220423A: Detection by VZLUSAT-2
  81. Konus-Wind detection of GRB 220427A
  82. GRB 220427A: Swift-XRT refined Analysis
  83. GRB 220427A: Enhanced Swift-XRT position
  84. GRB 220426A: Tiled Swift observations
  85. GRB 220427A: Swift detection of a burst with an optical counterpart
  86. Konus-Wind detection of GRB 220426A
  87. IPN triangulation of GRB 220426A
  88. GRB 220426C: Swift/BAT-GUANO detection outside the coded FOV (short)
  89. Fermi GRB 220426A: Global MASTER-Net observations report
  90. GRB 220426A: Fermi GBM detection
  91. GRB 220426A: Swift/BAT-GUANO detection outside the coded FOV
  92. Fermi GRB 220426B: Global MASTER-Net observations report
  93. GRB 220426B: Fermi GBM Final Real-time Localization
  94. GRB 220426A: BALROG localization (Fermi Trigger 672648596/ GRB 220426285)
  95. Correction to 31937: GRB 220421B: Detection by VZLUSAT-2
  96. GRB 220423A: Swift/BAT-GUANO detection outside the coded FOV
  97. On the AGILE detection of GRB 220423A
  98. GRB 220423A: AGILE detection
  99. GRB 220421B: Detection by VZLUSAT-2
  100. GRB 220421A: Fermi GBM observation

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