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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 210618A: Swift-XRT observations
  2. GRB 210618A: DDOTI upper limit for the optical afterglow
  3. GRB 210618A: Swift detection of a burst
  4. Swift GRB210618.07: Global MASTER-Net observations report
  5. GRB 210610B: Swift/UVOT Detection
  6. GRB 210610A: Swift/UVOT Detection
  7. GRB 201008A: Fermi GBM observation
  8. GRB 210323B: Fermi GBM observation
  9. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  10. Swift ToO Observations of HAWC transient J0020+3108
  11. GRB 210605B: Swift-XRT afterglow detection
  12. GRB 210610A: Fermi GBM observations
  13. GRB 210610A: CAHA 2.2m Second Epoch
  14. GRB 210421B: Fermi GBM detection
  15. Swift GRB210612.54: Global MASTER-Net observations report
  16. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  17. GRB210610B: SARA-KP 0.9m Optical Afterglow Detection
  18. GRB 210610B: MITSuME Akeno optical observation
  19. GRB 201228B: Fermi GBM observation
  20. GRB 210610B: VLA detection
  21. GRB 210610A: CAHA 2.2m observations and light-curve behavior
  22. GRB 210606A: Fermi GBM detection
  23. GRB 210605B: Fermi GBM detection
  24. GRB 210610B: Swift-XRT refined Analysis
  25. GRB 210610B: Swift-BAT refined analysis
  26. GRB 210610B: KAIT Optical Detection
  27. GRB 210610A: KAIT Optical Detection
  28. GRB 210610B: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  29. GRB 210610A: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  30. GRB 210610B: Fermi GBM detection
  31. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  32. Konus-Wind detection of GRB 210610A
  33. Konus-Wind detection of GRB 210610B
  34. GRB 210610B: AGILE detection
  35. GRB 210610B: GOTO confirmation of afterglow detection
  36. GRB 210610A: Swift-XRT refined Analysis
  37. GRB 210610B: RATIR Optical and NIR Observations
  38. GRB 210610B: Enhanced Swift-XRT position
  39. GRB 210610B: SAO RAS optical observations
  40. GRB 210610A: Swift-BAT refined analysis
  41. GRB 210610A: 1.5m OSN optical observation
  42. GRB210610B: MeerLICHT multi-colour photometry
  43. GRB 210610B: BOOTES-2/TELMA optical observation
  44. Swift GRB 210610B: Global MASTER-Net observations report
  45. GRB 210610B: GIT optical detection
  46. Swift GRB210610.83: Global MASTER-Net OT detection
  47. GRB 210606A: Swift-XRT afterglow detection
  48. GRB 210610B: Swift detection of a burst with bright optical afterglow
  49. GRB 210610A: MITSuME Ishigaki optical observation
  50. GRB210610A: MeerLICHT multi-colour photometry
  51. Swift GRB 210610A: Global MASTER-Net observations report
  52. Swift GRB 210610A: MASTER optical counterpart observation
  53. GRB 210610A: Enhanced Swift-XRT position
  54. GRB 210610A: GIT optical detection
  55. GRB 210610A: Xinglong-2.16m optical afterglow observations
  56. GRB 210610A: MITSuME Akeno optical observation
  57. GRB 210610A: Swift detection of a burst with an optical counterpart
  58. IPN triangulation of GRB 210606B
  59. GRB 210605B: Swift-XRT observations
  60. IPN triangulation of GRB 210605A (short)
  61. GRB 210606A: 1.5m OSN optical upper limit
  62. GECAM Sub-Threshold Detection of new magnetar Swift SGR J1555.2-5402
  63. GRB 210606A: Swift ToO observations
  64. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  65. GRB 210605B: Swift ToO observations
  66. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  67. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  68. Fermi GBM Sub-Threshold Detection of new Swift SGR J1555.2-5402
  69. SGR J1555.2-5402: Swift-BAT refined analysis
  70. Swift J1555.2-5402: Swift XRT refined analysis of the new SGR
  71. NICER discovery of 3.86 s pulsations from a new magnetar: SGR J1555.2-5402
  72. Swift Detection of probable new Swift SGR J1555.2-5402
  73. Swift GRB210603.41: Global MASTER-Net observations report
  74. GRB 210527A: Swift-BAT refined analysis
  75. GRB 210527A: Swift/UVOT Observations
  76. GRB 210527A: GIT optical upper limit
  77. Swift GRB 210527A: Global MASTER-Net observations report
  78. GRB 210527A: Swift-XRT refined Analysis
  79. GRB 210527A: Enhanced Swift-XRT position
  80. GRB 210527A: Swift-XRT observations
  81. GRB 210527A: Swift detection of a burst
  82. IPN triangulation of GRB 210524A
  83. GRB 210520A: Swift-XRT observations
  84. GRB210413B: further Swift-XRT observations
  85. GRB 210520A: Tiled Swift observations
  86. GRB 210520A: Fermi-LAT detection
  87. GRB 210517A: KCT optical upper limit
  88. Konus-Wind detection of GRB 210514A
  89. GRB 210517A: Swift-BAT refined analysis
  90. GRB 210517A: Swift-XRT refined Analysis
  91. GRB 210517A: Swift/UVOT Upper Limits
  92. GRB 210515C: Swift/UVOT Upper Limits
  93. GRB 210517A: AGILE detection
  94. GRB 210514A: CALET Gamma-Ray Burst Monitor detection
  95. GRB 210517A: Enhanced Swift-XRT position
  96. Swift GRB 210517A: Global MASTER-Net observations report
  97. GRB 210517A: Swift detection of a burst
  98. GRB 210515C: LCO Optical Upper Limit
  99. GRB 210504A: LCO Optical Afterglow Detection
  100. GRB 210514A: Swift/UVOT Upper Limits

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