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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"

27967 results found.

  1. GRB 201008A: Fermi GBM observation
  2. GRB 210323B: Fermi GBM observation
  3. GRB 210615A: Fermi GBM Final Real-time Localization
  4. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  5. Swift ToO Observations of HAWC transient J0020+3108
  6. GRB 210605B: Swift-XRT afterglow detection
  7. GRB 210610A: Fermi GBM observations
  8. GRB 210610A: CAHA 2.2m Second Epoch
  9. GRB 210610B: Continued KAIT Optical Detection
  10. GRB 210421B: Fermi GBM detection
  11. Swift GRB210612.54: Global MASTER-Net observations report
  12. GRB 210607C: AstroSat CZTI detection
  13. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  14. GRB210610B: SARA-KP 0.9m Optical Afterglow Detection
  15. GRB 210610B: MITSuME Akeno optical observation
  16. GRB 201228B: Fermi GBM observation
  17. GRB 210610B: VLA detection
  18. GRB 210610B: ALMA detection
  19. GRB 210610A: CAHA 2.2m observations and light-curve behavior
  20. GRB 210606A: Fermi GBM detection
  21. GRB 210605B: Fermi GBM detection
  22. GRB 210610B: Swift-XRT refined Analysis
  23. GRB 210610B: Swift-BAT refined analysis
  24. GRB 210610B: Zwicky Transient Facility afterglow detection
  25. GRB 210610B: KAIT Optical Detection
  26. GRB 210610A: KAIT Optical Detection
  27. GRB 210607C: Insight-HXMT/HE 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 210610A: RATIR Optical and NIR Detection
  38. GRB 210610B: RATIR Optical and NIR Observations
  39. GRB 210610B: Enhanced Swift-XRT position
  40. GRB 210610B: SAO RAS optical observations
  41. GRB 210610A: Swift-BAT refined analysis
  42. GRB 210610A: 1.5m OSN optical observation
  43. GRB210610B: MeerLICHT multi-colour photometry
  44. GRB 210610B: BOOTES-2/TELMA optical observation
  45. Swift GRB 210610B: Global MASTER-Net observations report
  46. GRB 210610B: GIT optical detection
  47. Swift GRB210610.83: Global MASTER-Net OT detection
  48. GRB 210606A: Swift-XRT afterglow detection
  49. GRB 210610B: Swift detection of a burst with bright optical afterglow
  50. GRB 210610A: MITSuME Ishigaki optical observation
  51. GRB210610A: MeerLICHT multi-colour photometry
  52. Swift GRB 210610A: Global MASTER-Net observations report
  53. Swift GRB 210610A: MASTER optical counterpart observation
  54. GRB 210610A: Enhanced Swift-XRT position
  55. GRB 210610A: Xinglong-2.16m redshift
  56. GRB 210610A: GIT optical detection
  57. GRB 210610A: Xinglong-2.16m optical afterglow observations
  58. GRB 210610A: MITSuME Akeno optical observation
  59. GRB 210610A: Swift detection of a burst with an optical counterpart
  60. GRB 210607B: Insight-HXMT/HE detection
  61. GRB 210605A: CALET Gamma-Ray Burst Monitor detection
  62. Konus-Wind detection of GRB 210606B
  63. IPN triangulation of GRB 210606B
  64. IceCube-210608A: IceCube observation of a high-energy neutrino candidate track-like event
  65. GRB 210607A/MAXI J1733-222: MAXI/GSC detection
  66. GRB 210606B: Fermi GBM detection
  67. GRB 210605B: Swift-XRT observations
  68. Konus-Wind detection of GRB 210602A
  69. Konus-Wind detection of GRB 210605A (short/hard)
  70. IPN triangulation of GRB 210605A (short)
  71. GRB 210606B: AGILE detection
  72. GRB 210606A: 1.5m OSN optical upper limit
  73. GECAM Sub-Threshold Detection of new magnetar Swift SGR J1555.2-5402
  74. GRB 210606B: GECAM detection
  75. GRB 210606A: Swift ToO observations
  76. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  77. GRB 210605B: Swift ToO observations
  78. GRB 210606A: Fermi GBM Final Real-time Localization
  79. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  80. GRB 210605B: Fermi GBM Final Real-time Localization
  81. GRB 210605A: Fermi GBM Final Real-time Localization
  82. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  83. Fermi GBM Sub-Threshold Detection of new Swift SGR J1555.2-5402
  84. SGR J1555.2-5402: Swift-BAT refined analysis
  85. Swift J1555.2-5402: Swift XRT refined analysis of the new SGR
  86. NICER discovery of 3.86 s pulsations from a new magnetar: SGR J1555.2-5402
  87. Swift Detection of probable new Swift SGR J1555.2-5402
  88. Swift GRB210603.41: Global MASTER-Net observations report
  89. GRB 210602A: CALET Gamma-Ray Burst Monitor detection
  90. GRB 210602B: GECAM detection
  91. GRB 210529A: GECAM detection
  92. GRB 210602A: MAXI/GSC detection
  93. GRB 210601A: Fermi GBM Final Real-time Localization
  94. IPN triangulation of GRB 210531A
  95. GRB210529B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 644025222)
  96. GRB 210531A: AstroSat CZTI detection
  97. GRB 210531A: AGILE/MCAL detection (Fermi Trigger 644155206 / GRB 210531500)
  98. GRB 210529B: Fermi GBM Final Real-time Localization
  99. GRB 210529A: Fermi GBM Final Real-time Localization
  100. GRB 210528A: Fermi GBM detection

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