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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"

27971 results found.

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

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