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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"

27969 results found.

  1. GRB 210411C: BOOTES-4/MET optical upper limit
  2. GRB 210411C: LCO Optical Afterglow Candidate
  3. GRB 210411C: Enhanced Swift-XRT position
  4. GRB 210406A: 10.4m GTC follow-up observation
  5. Konus-Wind detection of GRB 210410A
  6. GRB 210411D: Fermi GBM Final Real-time Localization
  7. GRB 210411C: Swift detection of a burst with an optical counterpart
  8. GRB 210410A: Swift-BAT refined analysis
  9. GRB 210411B: Fermi GBM Final Real-time Localization
  10. GRB 210410A: Swift-XRT refined Analysis
  11. GRB 210411A: Fermi GBM Final Real-time Localization
  12. GRB 210410A: Fermi GBM detection
  13. GRB 210410A: Swift/UVOT Upper Limits
  14. GRB 210406A: Swift-XRT observations
  15. GRB 210410A: RATIR Optical and NIR Observations
  16. GRB 210409A: GECAM detection
  17. GRB 210410A: AGILE detection of a burst
  18. GRB 210410A: Fermi-LAT detection
  19. GRB210410A: Candidate optical afterglow by Ondrejov D50
  20. GRB 210410A: Swift XRT localization
  21. GRB 210410A: Fermi GBM Final Real-time Localization
  22. Swift Triggers 1042031 and 1042032 are not astrophysical events
  23. GRB 210406A: Swift ToO observations
  24. GRB 210406B: Fermi GBM detection
  25. Konus-Wind detection of GRB 210406A
  26. GRB 210406A: Fermi GBM detection
  27. GRB 210406A: Konkoly Obs. optical upper limit
  28. GRB 210406A: BOOTES-4/MET optical upper limit
  29. GRB 210402A: MASTER prompt and follow up optical observation
  30. GRB 210402A: Swift/UVOT Upper Limits
  31. GRB 210402A: Fermi GBM detection
  32. GRB 210402A: Swift-BAT refined analysis
  33. GRB 210207B: Prompt and very late time observations with HCT.
  34. GRB 210401A: GECAM detection
  35. GRB 210402A: NOT optical afterglow candidate
  36. GRB 210402A: BOOTES-network early optical upper limit
  37. GRB 210403A: Swift-BAT refined analysis
  38. GRB 210402A: LBT observations
  39. GRB 210402A: DDOTI Upper Limits
  40. Swift GRB210403.35: Global MASTER-Net observations report
  41. GRB 210402A: Swift-XRT refined Analysis
  42. GRB 210330A: AstroSat CZTI detection
  43. GRB 210403A: Swift detection of a burst
  44. GRB 210402A: Montarrenti Observatory upper limit
  45. GRB 210328A: AstroSat CZTI detection
  46. Konus-Wind detection of GRB 210401A
  47. GRB 210402A: Swift detection of a burst
  48. Swift GRB210402.92: Global MASTER-Net observations report
  49. GRB 210401A: Fermi GBM Final Real-time Localization
  50. GRB 210328A: GECAM detection
  51. GRB 210330A: GECAM detection
  52. GRB 210324A: AstroSat CZTI detection
  53. GRB 210324C: AstroSat CZTI detection
  54. GRB 210328A: Fermi GBM Final Real-time Localization
  55. GRB 210326A: Insight-HXMT/HE detection
  56. GRB 210326A: Fermi GBM Final Localization
  57. Konus-Wind detection of GRB 210324C
  58. IPN triangulation of GRB 210324C
  59. GRB 210323A: Insight-HXMT/HE detection
  60. GRB 210321A: OSN Upper Limit
  61. GRB 210323A: MASTER optical observation
  62. GRB 210323A: Swift-BAT refined analysis
  63. GRB 210323A: Gemini-North Optical Source Detection
  64. GRB 210324C: Fermi GBM Final Real-time Localization
  65. Short GRB 210323A: GTC Observations
  66. GRB 210312B: OSN Afterglow Observations
  67. GRB 210324B: Fermi GBM Final Real-time Localization
  68. GRB 210323B: Swift ToO observations
  69. Konus-Wind detection of GRB 210323A (short)
  70. GRB 210323A: Swift/UVOT Upper Limits
  71. GRB 210323A: Kitab optical upper limit
  72. GRB 210323A: Fermi GBM detection
  73. GRB 210323A: Mondy optical observations, counterpart detection
  74. GRB 210324A: Fermi GBM Final Real-time Localization
  75. GRB 210318A: Swift/UVOT Upper Limits
  76. GRB 210323A: Swift-XRT refined Analysis
  77. GRB 210323A: Enhanced Swift-XRT position
  78. Swift GRB 210323A: Global MASTER-Net observations report
  79. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  80. GRB 210323A: Swift detection of a short burst
  81. GRB 210321A: Swift/UVOT Detection
  82. Konus-Wind detection of GRB 210321A
  83. GRB 210318B: Swift/UVOT Upper Limits
  84. GRB 210321A: Swift-BAT refined analysis
  85. IceCube 135113_19489408.amon: Swift-XRT observations
  86. IceCube Astrotrack Bronze 135113_19489408.amon is likely background
  87. GRB 210321A: Swift-XRT refined Analysis
  88. GRB 210321A: NOT optical afterglow detection and redshift limit
  89. GRB 210321A: MASTER optical observation
  90. GRB 210321A: Enhanced Swift-XRT position
  91. GRB 210321A: DDOTI Afterglow Confirmation
  92. GRB 210321A: Swift/UVOT Detection
  93. GRB 210321A: Swift-XRT observations
  94. GRB 210321A: Swift detection of a burst
  95. GRB 210320A: MAXI/GSC detection
  96. GRB 210318B: MITSuME Okayama optical upper limits
  97. GRB 210318A: Swift-BAT refined analysis
  98. GRB 210318A: Swift-XRT refined Analysis
  99. GRB 210318A: Enhanced Swift-XRT position
  100. Swift GRB210318.13: Global MASTER-Net observations report

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