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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"

21525 results found.

  1. GRB 210517A: VLT/X-shooter optical afterglow and redshift
  2. GRB 210517A: AGILE detection
  3. GRB 210514A: CALET Gamma-Ray Burst Monitor detection
  4. GRB 210517A: Enhanced Swift-XRT position
  5. Swift GRB 210517A: Global MASTER-Net observations report
  6. GRB 210517A: Swift detection of a burst
  7. GRB 210515C: LCO Optical Upper Limit
  8. GRB 210504A: LCO Optical Afterglow Detection
  9. GRB 210514A: Swift/UVOT Upper Limits
  10. GRB 210515C: Swift-XRT refined Analysis
  11. Swift GRB210515.83: Global MASTER-Net observations report
  12. GRB 210515C: Swift-BAT refined analysis
  13. GRB 210515C: Swift detection of a burst
  14. GRB 210514A: Swift-BAT refined analysis
  15. Swift GRB210514.71: Global MASTER-Net observations report
  16. GRB 210514A: Swift XRT light curve is fading
  17. GRB 210514A: Swift-XRT refined Analysis
  18. GRB 210514A: Enhanced Swift-XRT position
  19. GRB 210514A: update on the BAT trigger time and burst duration
  20. GRB 210514A: Swift detection of a burst
  21. IPN triangulation of GRB 210427A
  22. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  23. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  24. Swift trigger 1047857 is 4U 1700-377
  25. GRB 210509A: RATIR Optical and NIR Upper Limits
  26. GRB 210509A: Swift/UVOT Upper Limits
  27. GRB 210509A: Swift-XRT refined Analysis
  28. GRB 210509A: Swift-BAT refined analysis
  29. Swift GRB 210509A: Global MASTER-Net observations report
  30. GRB 210509A: Enhanced Swift-XRT position
  31. GRB 210509A: BOOTES-4/MET optical upper limit
  32. GRB 210509A: Swift-XRT observations
  33. GRB 210509A: Swift detection of a burst
  34. GRB 210506A: Swift/BAT-GUANO position retraction
  35. IPN triangulation of GRB 210506A
  36. GRB 210506A: Swift-XRT observations
  37. GRB 210506A: Nanshan/NEXT optical upper limit
  38. GRB 210506A: TNG NIR upper limits
  39. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  40. GRB 210506A: Swift ToO observations
  41. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  42. GRB 210504A: Lowell Discovery Telescope optical observations
  43. GRB 210504A: Swift-XRT refined Analysis
  44. GRB 210504A: Swift-BAT refined analysis
  45. GRB 210504A: MITSuME Akeno optical upper limits
  46. GRB 210504A: AST3-3 YaoAn Optical Upper Limit
  47. GRB 210504A: Swift/UVOT Detection
  48. GRB 210504A: BOOTES-4/MET optical upper limit
  49. Swift GRB210504.58: Global MASTER-Net observations report
  50. GRB 210504A: update on the BAT trigger time and burst duration
  51. GRB 210504A: Swift detection of a burst
  52. Swift GRB210502.74: Global MASTER-Net observations report
  53. Swift Detection of MAXI J1803-298 including an optical counterpart
  54. GRB 210430A: BOOTES-1 optical limit
  55. GRB 210430A: Swift-BAT refined analysis
  56. Swift GRB210430.45: Global MASTER-Net observations report
  57. GRB 210430A: Swift detection of a burst
  58. GRB 210413B: Swift/UVOT Observations
  59. Delayed GRB GCN Notices from Swift
  60. GRB 210323B: Swift-XRT observations
  61. Swift Trigger 1045571 is not a GRB
  62. GRB 210422A: Swift-BAT refined analysis
  63. GRB 210421A: Swift-BAT refined analysis
  64. GRB 210421B: Swift-XRT observations
  65. GRB 210421B: AstroSat CZTI detection
  66. GRB 210421A: GECAM detection
  67. GRB 210421B: AstroSat CZTI detection
  68. Swift GRB210422.74: Global MASTER-Net observations report
  69. GRB 210422A: Swift detection of a burst
  70. GRB 210421A: Swift/UVOT Upper Limits
  71. GRB 210421A: MITSuME Akeno optical upper limits
  72. GRB 210420B: Swift-BAT refined analysis
  73. GRB 210421B: Swift ToO observations
  74. GRB 210421B: Swift/BAT-GUANO detection and arcminute localization
  75. GRB 210420B: Swift-XRT refined Analysis
  76. GRB 210421A: Swift-XRT refined Analysis
  77. GRB 210419C: Swift/UVOT Upper Limits
  78. GRB 210421A: Enhanced Swift-XRT position
  79. GRB 210420B: Swift/UVOT Detection
  80. GRB 210420B: KAIT Optical Observations
  81. GRB 210419C: MITSuME Akeno optical upper limits
  82. GRB 210420B: DDOTI Detection of the Afterglow
  83. GRB 210421A: DDOTI Upper Limit
  84. GRB 210419C: Swift-BAT refined analysis
  85. GRB 210420B: update on the BAT trigger time
  86. GRB 210420B: Montarrenti Observatory optical afterglow detection
  87. Swift GRB 210421A: Global MASTER-Net observations report
  88. GRB 210421A: Swift detection of a burst
  89. GRB 210420B: AST3-3 YaoAn Optical Observation
  90. GRB 210420B: BOOTES-4/MET optical afterglow detection
  91. GRB 210420B: Optical observations
  92. GRB 210420B: MASTER optical counterpart detection
  93. GRB 210420B: Swift detection of a burst
  94. GRB 210419C: RATIR Optical and NIR Upper Limits
  95. GRB 210419C: Montarrenti Observatory Upper Limit
  96. GRB 210419A: Swift/UVOT Upper Limits
  97. GRB 210419C: KAIT Optical Upper Limit
  98. GRB 210419C: Enhanced Swift-XRT position
  99. GRB 210419A: Swift-BAT refined analysis
  100. Swift GRB210419.98: Global MASTER-Net observations report

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