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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"

26123 results found.

  1. GRB 210826A: Swift-XRT observations
  2. GRB 210822A: CAHA 2.2m observations
  3. GRB 210824A: Swift-BAT refined analysis
  4. GRB 210826A: Fermi-LAT detection
  5. GRB 210826A: Tiled Swift observations
  6. GRB 210824A: MITSuME Akeno optical upper limits
  7. Swift GRB210825.29: Global MASTER-Net observations report
  8. GRB 210822A: TSHAO continued optical observation
  9. GRB 210822A: VLA detection
  10. GRB 210822A: TSHAO optical observation
  11. Swift detection of an outburst from SGR Swift J1555.2-5402
  12. GRB 210822A: Swift/UVOT Detection
  13. Swift GRB 210824A: Global MASTER-Net observations report
  14. GRB 210824A: BOOTES-5/JGT optical upper limit
  15. GRB 210824A: Fermi GBM Observation
  16. GRB 210824A: Nanshan/NEXT optical upper limit
  17. GRB 210824A: Swift-XRT refined Analysis
  18. GRB 210822A: GROND observations
  19. GRB 210824A: Enhanced Swift-XRT position
  20. GRB 210822A: Abbey Ridge Observatory optical afterglow observation
  21. GRB 210824A: Swift detection of a burst
  22. GRB 210822B: DDOTI Upper Limits on the Afterglow
  23. GRB 210822A: Detection by GRBAlpha
  24. GRB 210822A: GECAM refined analysis
  25. GRB 210820A: GROND observations
  26. Konus-Wind detection of GRB 210822A
  27. GRB 210822A: AstroSat CZTI detection
  28. GRB 210822A: NOT photometry and spectroscopy
  29. GRB 210822A: Swift-XRT refined Analysis
  30. GRB 210822A: Swift-BAT refined analysis
  31. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  32. GRB 210822A: Fermi-LAT detection
  33. GRB 210820A: Swift/UVOT Detection
  34. GRB 210822A: Nanshan/NEXT optical observations
  35. GRB 210822A: Enhanced Swift-XRT position
  36. Swift GRB 210822A: Global MASTER-Net observations report
  37. GRB 210822A: KAIT Optical Afterglow Confirmation
  38. GRB 210822A: GECAM detection
  39. GRB 210822A: Swift detection of a burst with an optical afterglow
  40. GRB 210820A: Swift-BAT refined analysis
  41. GRB 210820A: LT optical upper limit
  42. GRB 210820A: LCO Optical Upper Limit
  43. GRB 210820A: RATIR Optical Detections
  44. GRB 210820A: NOT optical upper limit
  45. GRB 210820A: Nanshan/NEXT optical upper limit
  46. GRB 210820A: Swift-XRT refined Analysis
  47. GRB 210820A: Enhanced Swift-XRT position
  48. Swift GRB 210820A: Global MASTER-Net observations report
  49. GRB 210820A: Swift detection of a burst with an optical counterpart
  50. Swift GRB210818.68: Global MASTER-Net observations report
  51. Swift GRB 210818A: Global MASTER-Net observations report
  52. GRB 210818A: Swift-XRT refined Analysis
  53. GRB 210818A: Swift-BAT refined analysis
  54. GRB 210726A: VLA radio afterglow detection
  55. Konus-Wind detection of GRB 210818A
  56. Swift Trigger 1069242 is Cyg X-1
  57. GRB 210818A: AstroSat CZTI detection
  58. GRB 210818A: AGILE detection
  59. GRB 210818A: Enhanced Swift-XRT position
  60. GRB 210818A: Swift detection of a burst with an optical counterpart
  61. GRB 210712A: Fermi GBM observation
  62. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  63. GRB 210730A: Tautenburg observations
  64. GRB 210807A: Tautenburg observations
  65. GRB 210807C: Swift-BAT refined analysis
  66. GRB 210807A: Detection by GRBAlpha
  67. GRB 210807A: Swift-BAT refined analysis
  68. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  69. GRB 210807C: Swift-XRT refined Analysis
  70. GRB 210807C: Fermi GBM detection
  71. GRB 210807C: Swift/UVOT Upper Limits
  72. GRB 210807A: Swift/UVOT Detection
  73. GRB 210807A: Swift-XRT refined Analysis
  74. GRB 210807C: Enhanced Swift-XRT position
  75. GRB 210610B: Assy optical observations
  76. Swift GRB210807.74: Global MASTER-Net observations report
  77. Swift GRB210807.96: Global MASTER-Net observations report
  78. GRB 210807C: Swift detection of a burst
  79. Swift GRB 210807A: Global MASTER-Net observations report
  80. Swift GRB210807.79: Global MASTER-Net observations report
  81. Swift GRB210807.78: Global MASTER-Net observations report
  82. GRB 210807A: Enhanced Swift-XRT position
  83. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  84. GRB 210807A: Swift detection of a burst with an optical counterpart
  85. IPN Triangulation of a bright burst from SGR 1935+2154
  86. GRB 210802A: MITSuME Okayama optical upper limits
  87. GRB 210802A: DDOTI Upper Limits
  88. GRB 210802A: BOOTES-2/TELMA optical upper limit
  89. GRB 210802A: Swift-XRT afterglow detection
  90. GRB 210802A: Fermi-LAT detection
  91. GRB 210802A: Tiled Swift observations
  92. GRB 210731A: continued GROND observations
  93. GRB 210731A: VLT/X-shooter redshift
  94. GRB 210731A: KAIT Optical Detection
  95. GRB 210731A: Swift-BAT refined analysis
  96. GRB 210731A: MASTER optical afterglow detection
  97. GRB 210731A: Swift-XRT refined Analysis
  98. GRB 210731A: GROND observations
  99. GRB 210731A: Fermi GBM Observation
  100. GRB 210731A: Swift/UVOT Detection of an optical afterglow

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