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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"

19611 results found.

  1. GRB 220826A: Swift-BAT refined analysis
  2. GRB 220826A: Fermi GBM observation
  3. GRB 220826A: Swift-XRT refined Analysis
  4. GRB 220825A: Fermi GBM observation
  5. GRB 220826A: Lesedi optical afterglow detection
  6. GRB 220826A: Swift/UVOT Detection
  7. Swift GRB 220826A: Global MASTER-Net observations report
  8. GRB 220826A: Enhanced Swift-XRT position
  9. GRB 220826A: Swift detection of a burst with an optical counterpart
  10. GRB 220825A: Swift/BAT-GUANO detection
  11. GRB 220823A: Fermi GBM detection
  12. GRB 220823A: Swift/BAT-GUANO detection of a short burst
  13. Konus-Wind detection of GRB 220813A
  14. GRB 220813A: VLT optical observations and possible host galaxy
  15. GRB 220813A: Swift/UVOT Detection
  16. GRB 220810A: Further Swift-XRT observations
  17. GRB 220813A: Swift-XRT refined Analysis
  18. Swift GRB 220813A: Global MASTER-Net observations report
  19. GRB 220813A: Enhanced Swift-XRT position
  20. GRB 220813A: Swift detection of a burst with an optical counterpart
  21. GRB 220810A: Swift-XRT observations
  22. GRB 220810A: Swift ToO observations
  23. GRB 220806A: Swift-BAT refined analysis
  24. GRB 220806A: Swift detection of a burst
  25. Swift GRB220806.76: Global MASTER-Net observations report
  26. Konus-Wind detection of GRB 220730A (short)
  27. GRB 220730A: Swift-BAT refined analysis
  28. GRB 220730A: Fermi GBM detection
  29. GRB 220730A: Swift-XRT afterglow detection
  30. GRB 220730A: Swift/UVOT Upper Limits
  31. GRB 220730A: Swift-XRT observations
  32. Swift GRB 220730A: Global MASTER-Net observations report
  33. GRB 220730A: Swift detection of a short hard burst
  34. GRB 220711B: CALET Gamma-Ray Burst Monitor detection
  35. GRB 220715B: Swift-BAT refined analysis
  36. GRB220714B: UVOT detections
  37. GRB 220715B: Fermi GBM detection
  38. GRB 220715B: Swift-XRT refined Analysis
  39. GRB 220715B: Swift/UVOT Upper Limits
  40. GRB 220715B: Enhanced Swift-XRT position
  41. GRB 220715B: BOOTES-network optical upper limits
  42. Swift GRB 220715B: Global MASTER-Net observations report
  43. GRB 220715B: Prompt enhanced Swift-XRT position
  44. GRB 220715B: Swift detection of a burst
  45. GRB 220714B: Swift-BAT refined analysis
  46. GRB 220714B: Fermi GBM observation
  47. GRB 220714B: LCO Optical Observations
  48. GRB 220714B: Swift-XRT refined Analysis
  49. Swift/BAT Trigger 1116172 (=GRB 220714A) is not a real astrophysical event
  50. GRB 220714B: UVOT afterglow discovery
  51. GRB 220714B: Enhanced Swift-XRT position
  52. GRB 220714B: Swift detection of a burst
  53. GRB 220714A: Possible Swift detection of a burst
  54. GRB 220710A: Swift/UVOT Upper Limits
  55. GRB 220711C: Fermi GBM Observation
  56. GRB 220710A: Swift-XRT afterglow detection
  57. GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
  58. GRB 220711B: GIT optical upper limits
  59. GRB 220710A: Swift ToO observations
  60. GRB 220710A: Swift/BAT-GUANO arcminute localization
  61. GRB 220711B: Swift-BAT refined analysis
  62. IPN triangulation of GRB 220711C (short)
  63. GRB 220711B: Swift-XRT refined Analysis
  64. GRB 220711B: Swift/UVOT Upper Limits
  65. GRB 220711B: Enhanced Swift-XRT position
  66. GRB 220711B: Fermi GBM Detection
  67. GRB 220711B: LCO Optical Upper Limits
  68. GRB 220711B: Swift detection of a burst
  69. GRB 220708B: GIT optical upper limits
  70. GRB 220708A: Swift-BAT refined analysis
  71. Konus-Wind detection of GRB 220708B
  72. GRB 220708B: CALET Gamma-Ray Burst Monitor detection
  73. GRB 220708B: Nanshan/NEXT optical upper limits
  74. GRB 220708A: Swift/UVOT Upper Limits
  75. GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
  76. GRB 220708A: Swift-XRT refined Analysis
  77. GRB 220706A: Swift/UVOT Upper Limits
  78. GRB 220708B: Swift-XRT afterglow detection
  79. GRB 220708A: BOOTES-5/JGT early optical upper limit
  80. GRB 220706A: Swift-BAT refined analysis
  81. GRB 220708A: Enhanced Swift-XRT position
  82. GRB 220708B: Swift ToO observations
  83. GRB 220708B: Swift/BAT-GUANO arcminute localization
  84. GRB 220708A: Swift-XRT observations
  85. GRB 220708A: Swift detection of a burst
  86. GRB 220706A: LCO Optical Upper Limits
  87. GRB 220706A: Swift-XRT refined Analysis
  88. GRB 220706A, GROND observations
  89. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  90. GRB 220706A: Nanshan/NEXT optical upper limits
  91. GRB 220706A: Enhanced Swift-XRT position
  92. Swift GRB 220706A: Global MASTER-Net observations report
  93. GRB 220706A: Zadko observatory - Gingin optical observations
  94. GRB 220706A: Prompt enhanced Swift-XRT position
  95. GRB 220706A: Swift detection of a burst
  96. GRB 220701A: Swift-BAT refined analysis
  97. GRB 220701A: MITSuME Akeno optical upper limits
  98. GRB 220701A: AbAO optical upper limit
  99. GRB 220627A: AstroSat CZTI detection
  100. GRB 220701A: Swift-XRT refined Analysis

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Download all Circulars as a .tar.gz archive (updated once a day):
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