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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"

19663 results found.

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

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