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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"

19662 results found.

  1. GRB 210610B: AGILE detection
  2. GRB 210610B: GOTO confirmation of afterglow detection
  3. GRB 210610A: Swift-XRT refined Analysis
  4. GRB 210610B: RATIR Optical and NIR Observations
  5. GRB 210610B: Enhanced Swift-XRT position
  6. GRB 210610B: SAO RAS optical observations
  7. GRB 210610A: Swift-BAT refined analysis
  8. GRB 210610A: 1.5m OSN optical observation
  9. GRB210610B: MeerLICHT multi-colour photometry
  10. GRB 210610B: BOOTES-2/TELMA optical observation
  11. Swift GRB 210610B: Global MASTER-Net observations report
  12. GRB 210610B: GIT optical detection
  13. Swift GRB210610.83: Global MASTER-Net OT detection
  14. GRB 210606A: Swift-XRT afterglow detection
  15. GRB 210610B: Swift detection of a burst with bright optical afterglow
  16. GRB 210610A: MITSuME Ishigaki optical observation
  17. GRB210610A: MeerLICHT multi-colour photometry
  18. Swift GRB 210610A: Global MASTER-Net observations report
  19. Swift GRB 210610A: MASTER optical counterpart observation
  20. GRB 210610A: Enhanced Swift-XRT position
  21. GRB 210610A: GIT optical detection
  22. GRB 210610A: Xinglong-2.16m optical afterglow observations
  23. GRB 210610A: MITSuME Akeno optical observation
  24. GRB 210610A: Swift detection of a burst with an optical counterpart
  25. IPN triangulation of GRB 210606B
  26. GRB 210605B: Swift-XRT observations
  27. IPN triangulation of GRB 210605A (short)
  28. GRB 210606A: 1.5m OSN optical upper limit
  29. GECAM Sub-Threshold Detection of new magnetar Swift SGR J1555.2-5402
  30. GRB 210606A: Swift ToO observations
  31. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  32. GRB 210605B: Swift ToO observations
  33. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  34. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  35. Fermi GBM Sub-Threshold Detection of new Swift SGR J1555.2-5402
  36. SGR J1555.2-5402: Swift-BAT refined analysis
  37. Swift J1555.2-5402: Swift XRT refined analysis of the new SGR
  38. NICER discovery of 3.86 s pulsations from a new magnetar: SGR J1555.2-5402
  39. Swift Detection of probable new Swift SGR J1555.2-5402
  40. Swift GRB210603.41: Global MASTER-Net observations report
  41. GRB 210527A: Swift-BAT refined analysis
  42. GRB 210527A: Swift/UVOT Observations
  43. GRB 210527A: GIT optical upper limit
  44. Swift GRB 210527A: Global MASTER-Net observations report
  45. GRB 210527A: Swift-XRT refined Analysis
  46. GRB 210527A: Enhanced Swift-XRT position
  47. GRB 210527A: Swift-XRT observations
  48. GRB 210527A: Swift detection of a burst
  49. IPN triangulation of GRB 210524A
  50. GRB 210520A: Swift-XRT observations
  51. GRB210413B: further Swift-XRT observations
  52. GRB 210520A: Tiled Swift observations
  53. GRB 210520A: Fermi-LAT detection
  54. GRB 210517A: KCT optical upper limit
  55. Konus-Wind detection of GRB 210514A
  56. GRB 210517A: Swift-BAT refined analysis
  57. GRB 210517A: Swift-XRT refined Analysis
  58. GRB 210517A: Swift/UVOT Upper Limits
  59. GRB 210515C: Swift/UVOT Upper Limits
  60. GRB 210517A: AGILE detection
  61. GRB 210514A: CALET Gamma-Ray Burst Monitor detection
  62. GRB 210517A: Enhanced Swift-XRT position
  63. Swift GRB 210517A: Global MASTER-Net observations report
  64. GRB 210517A: Swift detection of a burst
  65. GRB 210515C: LCO Optical Upper Limit
  66. GRB 210504A: LCO Optical Afterglow Detection
  67. GRB 210514A: Swift/UVOT Upper Limits
  68. GRB 210515C: Swift-XRT refined Analysis
  69. Swift GRB210515.83: Global MASTER-Net observations report
  70. GRB 210515C: Swift-BAT refined analysis
  71. GRB 210515C: Swift detection of a burst
  72. GRB 210514A: Swift-BAT refined analysis
  73. Swift GRB210514.71: Global MASTER-Net observations report
  74. GRB 210514A: Swift XRT light curve is fading
  75. GRB 210514A: Swift-XRT refined Analysis
  76. GRB 210514A: Enhanced Swift-XRT position
  77. GRB 210514A: update on the BAT trigger time and burst duration
  78. GRB 210514A: Swift detection of a burst
  79. IPN triangulation of GRB 210427A
  80. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  81. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  82. Swift trigger 1047857 is 4U 1700-377
  83. GRB 210509A: RATIR Optical and NIR Upper Limits
  84. GRB 210509A: Swift/UVOT Upper Limits
  85. GRB 210509A: Swift-XRT refined Analysis
  86. GRB 210509A: Swift-BAT refined analysis
  87. Swift GRB 210509A: Global MASTER-Net observations report
  88. GRB 210509A: Enhanced Swift-XRT position
  89. GRB 210509A: BOOTES-4/MET optical upper limit
  90. GRB 210509A: Swift-XRT observations
  91. GRB 210509A: Swift detection of a burst
  92. GRB 210506A: Swift/BAT-GUANO position retraction
  93. IPN triangulation of GRB 210506A
  94. GRB 210506A: Swift-XRT observations
  95. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  96. GRB 210506A: Swift ToO observations
  97. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  98. GRB 210504A: Lowell Discovery Telescope optical observations
  99. GRB 210504A: Swift-XRT refined Analysis
  100. GRB 210504A: Swift-BAT refined analysis

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