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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"

34073 results found.

  1. GRB 220511A: BOOTES-2/TELMA optical upper limit
  2. Fermi GRB 220512A: Global MASTER-Net observations report
  3. GRB 220512A: Fermi GBM Final Real-time Localization
  4. GRB 220511A: Swift ToO observations
  5. GRB 220511A: Swift/BAT-GUANO arcminute localization
  6. Fermi GRB 220511A: Global MASTER-Net observations report
  7. GRB 220511A: AGILE detection
  8. GRB 220511A: BALROG localization (Fermi Trigger 673969321/ GRB 220511571)
  9. GRB 220511A: Fermi GBM Final Real-time Localization
  10. GRB 220507A: AstroSat CZTI detection
  11. GRB 220506A: MITSuME Akeno optical upper limits
  12. GRB 220506A: GIT optical upper limit.
  13. GRB 220508A: Fermi GBM Final Real-time Localization
  14. GRB 220507A: Fermi GBM Final Localization
  15. GRB 220506A: BOOTES-5/JGT optical upper limit
  16. GRB 220506A: Swift-XRT afterglow detection
  17. GRB 220506A: Tiled Swift observations
  18. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  19. GRB 220430A: Nanshan/NEXT optical upper limit
  20. GRB 220430A: Nanshan/HMT optical upper limit
  21. GRB 220430A: GIT optical upper limits
  22. IPN triangulation of GRB 220423A
  23. GRB 220427A: LCO Optical Observations
  24. GRB 220501A: Swift-BAT refined analysis
  25. GRB 220427A: GRANDMA Early Optical Afterglow Detection
  26. GRB 220501A: BOOTES-1 optical upper limit
  27. GRB 220501A: Fermi GBM observation
  28. GRB 220430A: AstroSat CZTI detection
  29. GRB 220501A: GRANDMA/TJML Optical Observations
  30. GRB 220501A: Fermi GBM Final Real-time Localization
  31. GRB 220501A: Swift detection of a burst
  32. GRB 220430A: Swift-BAT refined analysis
  33. GRB 220430A: CAHA 2.2m telescope optical limit
  34. GRB 220430A: Swift-XRT refined Analysis
  35. Swift GRB 220430A: Global MASTER-Net observations report
  36. GRB 220430A: GRANDMA observations
  37. GRB 220430A: Mondy and AbAO optical upper limits
  38. GRB 220430A: AGILE detection
  39. GRB 220430A: MeerLICHT optical upper limits
  40. GRB 220430A: Enhanced Swift-XRT position
  41. GRB 220430A: Swift detection of a burst or Swift J0630.4+0932
  42. GRB 220427A: Swift-BAT refined analysis
  43. GRB 220427A: VLT/X-shooter photometry
  44. GRB 220426A: Swift-XRT and UVOT observations
  45. GRB 220423A: Detection by VZLUSAT-2
  46. Konus-Wind detection of GRB 220427A
  47. GRB 220427A: Swift-XRT refined Analysis
  48. GRB 220427A: Enhanced Swift-XRT position
  49. GRB 220426A: Tiled Swift observations
  50. GRB 220427A: Swift detection of a burst with an optical counterpart
  51. Konus-Wind detection of GRB 220426A
  52. IPN triangulation of GRB 220426A
  53. GRB 220426C: Swift/BAT-GUANO detection outside the coded FOV (short)
  54. Fermi GRB 220426A: Global MASTER-Net observations report
  55. GRB 220426A: Fermi GBM detection
  56. GRB 220426A: Swift/BAT-GUANO detection outside the coded FOV
  57. Fermi GRB 220426B: Global MASTER-Net observations report
  58. GRB 220426B: Fermi GBM Final Real-time Localization
  59. GRB 220426A: BALROG localization (Fermi Trigger 672648596/ GRB 220426285)
  60. Correction to 31937: GRB 220421B: Detection by VZLUSAT-2
  61. GRB 220423A: Swift/BAT-GUANO detection outside the coded FOV
  62. On the AGILE detection of GRB 220423A
  63. GRB 220423A: AGILE detection
  64. GRB 220421B: Detection by VZLUSAT-2
  65. GRB 220421A: Fermi GBM observation
  66. GRB 220421A: Swift/BAT-GUANO detection outside the coded FOV
  67. Fermi GBM trigger 672128054/220420260 is not a GRB
  68. GRB 220418B: Swift-XRT observations
  69. GRB 220418B Fermi GBM observation
  70. “GRB 220420A” is not a GRB
  71. GRB 220420A: Swift/BAT-GUANO detection outside the coded FOV
  72. GRB 220403C: Further Swift-XRT observations
  73. GRB 220418B: Swift ToO observations
  74. GRB 220417A: Fermi GBM detection
  75. GRB 220418B: Swift/BAT-GUANO refined location of a short burst
  76. IPN triangulation of GRB 220411A
  77. GRB 220418B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  78. GRB 220417A: Swift/BAT-GUANO detection outside the coded FOV
  79. GRB 220412B: Swift/UVOT Upper Limits
  80. Fermi GRB 220418A: Global MASTER-Net observations report
  81. GRB 220418B: Fermi GBM Final Real-time Localization
  82. GRB 220418A: Fermi GBM Final Real-time Localization
  83. Fermi GRB 220417A: Global MASTER-Net observations report
  84. GRB 220417A: Fermi GBM Final Real-time Localization
  85. GRB 220412B: Swift-BAT refined analysis
  86. Konus-Wind detection of GRB 220412B
  87. GRB 220412B: Fermi GBM observation
  88. Konus-Wind detection of GRB 220403C
  89. GRB 220408B: Fermi GBM observation
  90. Konus-Wind detection of GRB 220408B
  91. GRB 220412B: TNG optical observations
  92. GRB 220412A: GRANDMA observations
  93. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  94. GRB 220412A: BOOTES-network optical upper limits
  95. GRB 220412B: BOOTES-1 optical upper limit
  96. GRB 220412A: Swift-BAT refined analysis
  97. GRB 220412A: RATIR Observations of the Fading Afterglow
  98. GRB 220412B: Swift-XRT observations
  99. GRB 220408B: Fermi-LAT detection
  100. IPN triangulation of short/soft GRB 220406A

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