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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.

"200205A/SWIFT J0840.7-3516" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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"

19598 results found.

  1. GRB 210515C: Swift-XRT refined Analysis
  2. Swift GRB210515.83: Global MASTER-Net observations report
  3. GRB 210515C: Swift-BAT refined analysis
  4. GRB 210515C: Swift detection of a burst
  5. GRB 210514A: Swift-BAT refined analysis
  6. Swift GRB210514.71: Global MASTER-Net observations report
  7. GRB 210514A: Swift XRT light curve is fading
  8. GRB 210514A: Swift-XRT refined Analysis
  9. GRB 210514A: Enhanced Swift-XRT position
  10. GRB 210514A: update on the BAT trigger time and burst duration
  11. GRB 210514A: Swift detection of a burst
  12. IPN triangulation of GRB 210427A
  13. Fermi GRB 210510A: Global MASTER-Net observations report
  14. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  15. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  16. Swift trigger 1047857 is 4U 1700-377
  17. GRB 210509A: RATIR Optical and NIR Upper Limits
  18. GRB 210509A: Swift/UVOT Upper Limits
  19. GRB 210509A: Swift-XRT refined Analysis
  20. GRB 210509A: Swift-BAT refined analysis
  21. Swift GRB 210509A: Global MASTER-Net observations report
  22. GRB 210509A: Enhanced Swift-XRT position
  23. GRB 210509A: BOOTES-4/MET optical upper limit
  24. GRB 210509A: Swift-XRT observations
  25. GRB 210509A: Swift detection of a burst
  26. GRB 210506A: Swift/BAT-GUANO position retraction
  27. IPN triangulation of GRB 210506A
  28. GRB 210506A: Swift-XRT observations
  29. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  30. GRB 210506A: Swift ToO observations
  31. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  32. GRB 210504A: Lowell Discovery Telescope optical observations
  33. GRB 210504A: Swift-XRT refined Analysis
  34. GRB 210504A: Swift-BAT refined analysis
  35. GRB 210504A: AST3-3 YaoAn Optical Upper Limit
  36. GRB 210504A: Swift/UVOT Detection
  37. GRB 210504A: BOOTES-4/MET optical upper limit
  38. Swift GRB210504.58: Global MASTER-Net observations report
  39. GRB 210504A: update on the BAT trigger time and burst duration
  40. GRB 210504A: Swift detection of a burst
  41. Swift GRB210502.74: Global MASTER-Net observations report
  42. Swift Detection of MAXI J1803-298 including an optical counterpart
  43. GRB 210430A: BOOTES-1 optical limit
  44. GRB 210430A: Swift-BAT refined analysis
  45. Swift GRB210430.45: Global MASTER-Net observations report
  46. GRB 210430A: Swift detection of a burst
  47. GRB 210413B: Swift/UVOT Observations
  48. Delayed GRB GCN Notices from Swift
  49. GRB 210323B: Swift-XRT observations
  50. Swift Trigger 1045571 is not a GRB
  51. GRB 210422A: Swift-BAT refined analysis
  52. GRB 210421A: Swift-BAT refined analysis
  53. GRB 210421B: Swift-XRT observations
  54. GRB 210421B: AstroSat CZTI detection
  55. GRB 210421A: GECAM detection
  56. GRB 210421B: AstroSat CZTI detection
  57. Swift GRB210422.74: Global MASTER-Net observations report
  58. GRB 210422A: Swift detection of a burst
  59. GRB 210421A: Swift/UVOT Upper Limits
  60. GRB 210421A: MITSuME Akeno optical upper limits
  61. GRB 210420B: Swift-BAT refined analysis
  62. GRB 210421B: Swift ToO observations
  63. GRB 210421B: Swift/BAT-GUANO detection and arcminute localization
  64. GRB 210420B: Swift-XRT refined Analysis
  65. GRB 210421A: Swift-XRT refined Analysis
  66. GRB 210419C: Swift/UVOT Upper Limits
  67. GRB 210421A: Enhanced Swift-XRT position
  68. GRB 210420B: Swift/UVOT Detection
  69. GRB 210420B: KAIT Optical Observations
  70. GRB 210419C: MITSuME Akeno optical upper limits
  71. GRB 210420B: DDOTI Detection of the Afterglow
  72. GRB 210421A: DDOTI Upper Limit
  73. GRB 210419C: Swift-BAT refined analysis
  74. GRB 210420B: update on the BAT trigger time
  75. GRB 210420B: Montarrenti Observatory optical afterglow detection
  76. Swift GRB 210421A: Global MASTER-Net observations report
  77. GRB 210421A: Swift detection of a burst
  78. GRB 210420B: AST3-3 YaoAn Optical Observation
  79. GRB 210420B: BOOTES-4/MET optical afterglow detection
  80. GRB 210420B: Optical observations
  81. GRB 210420B: MASTER optical counterpart detection
  82. GRB 210420B: Swift detection of a burst
  83. GRB 210419C: Montarrenti Observatory Upper Limit
  84. GRB 210419A: Swift/UVOT Upper Limits
  85. GRB 210419C: KAIT Optical Upper Limit
  86. GRB 210419C: Enhanced Swift-XRT position
  87. GRB 210419A: Swift-BAT refined analysis
  88. Swift GRB210419.98: Global MASTER-Net observations report
  89. GRB 210419A: Swift-XRT refined Analysis
  90. GRB 210419C: Swift detection of a burst
  91. Swift GRB 210419A: Global MASTER-Net observations report
  92. GRB 210419A: Enhanced Swift-XRT position
  93. GRB 210419A: LCO Optical Upper Limit
  94. GRB 210419A: Swift detection of a burst
  95. GRB 210413B: Swift-XRT observations
  96. GRB 210413B: LOAO optical upper limit
  97. GRB 210411C: A very significant early X-ray afterglow
  98. GRB 210413B: Swift ToO observations
  99. GRB 210413B: Swift/BAT detection and probable localization of a short burst
  100. GRB 210410A: AstroSat CZTI detection

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