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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"

19666 results found.

  1. GRB 211223C: BOOTES-4/MET optical upper limit
  2. Swift GRB 211223C: Global MASTER-Net observations report
  3. Fermi GBM Sub-Threshold Detection of GRB 211221A
  4. Fermi GBM Sub-Threshold Detection of GRB 211207A
  5. GRB 211221A: Swift-BAT refined analysis
  6. GRB 211223C: Swift detection of a burst
  7. GRB 211219A: AstroSat CZTI detection
  8. GRB 211221A: Swift-XRT refined Analysis
  9. GRB 211221A: BOOTES-4/MET optical upper limit
  10. GRB 211221A: MeerLICHT optical limits
  11. GRB 211221A: Enhanced Swift-XRT position
  12. Swift GRB 211221A: Global MASTER-Net observations report
  13. GRB 211221A: Swift detection of a burst
  14. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  15. GRB 211216A: Fermi GBM observation
  16. GRB 211216A: Swift/BAT-GUANO detection outside the coded FOV
  17. GRB 211211A: Insight-HXMT/HE detection
  18. GRB 211211A: HCT and GIT optical follow up observations
  19. GRB 211211A: CALET Gamma-Ray Burst Monitor detection
  20. GRB 211211A: Swift/UVOT detection
  21. GRB 211211A: NOT optical spectroscopy
  22. Swift GRB 211211A: Global MASTER-Net observations report
  23. GRB 211211A: LCO Optical Observations
  24. GRB 211211A: Nanshan/NEXT optical observations
  25. GRB 211211A: Swift-XRT refined Analysis
  26. GRB 211211A: Fermi GBM observation
  27. GRB 211211A: Swift-BAT refined analysis
  28. GRB 211211A: Enhanced Swift-XRT position
  29. GRB 211207A: Swift/UVOT Detection
  30. GRB 211211A: KAIT Optical Afterglow Candidate
  31. GRB 211211A: Swift detection of a bright burst
  32. GRB 211207A: Swift-BAT refined analysis
  33. GRB 211204C: Fermi GBM detection
  34. GRB 211207A: Swift-XRT refined Analysis
  35. GRB 211207A: Enhanced Swift-XRT position
  36. Swift GRB 211207A: Global MASTER-Net observations report
  37. GRB 211207A: Swift detection of a burst with an optical counterpart
  38. GRB 211206A: AstroSat CZTI detection
  39. GRB 211204C: AstroSat CZTI detection
  40. IPN triangulation of GRB 211204C
  41. GRB 211206A: Swift/BAT-GUANO detection outside the coded FOV
  42. GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV
  43. GRB 211124A: Fermi GBM Observation
  44. Swift Trigger 1086826 (possible GRB 211203A) is likely not an astrophysical event
  45. Swift GRB 211203A: Global MASTER-Net observations report
  46. Fermi GBM Upper limits for GRB 211203A
  47. GRB 211203A: Swift detection of a burst
  48. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  49. GRB 211106A: GECAM detection
  50. GRB 211129A: Swift-BAT refined analysis
  51. GRB 211129A: Swift-XRT refined Analysis
  52. GRB 211129A: Swift/UVOT Upper Limits
  53. GRB 211129A: Fermi GBM observation
  54. Swift GRB 211129A: Global MASTER-Net observations report
  55. GRB 211129A: Nanshan/NEXT optical upper limit
  56. GRB 211129A: Enhanced Swift-XRT position
  57. IPN triangulation of GRB 211118A
  58. GRB 211129A: MITSuME Akeno optical upper limits
  59. GRB 211129A: Swift detection of a burst
  60. GRB 211120548: Fermi GBM observation
  61. Chandra observations of GRB 210905A
  62. GRB 211118A: Fermi GBM detection
  63. IPN triangulation of GRB 211124A (short)
  64. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  65. Trigger_21473: Tiled Swift observations
  66. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  67. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  68. GRB 211118A: AstroSat CZTI detection
  69. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  70. Konus-Wind detection of GRB 211107B
  71. GRB 211106A: Swift/UVOT upper limits
  72. IPN triangulation of GRB 211106A (short)
  73. GRB 211107B: Swift-XRT afterglow detection
  74. GRB 211106A: Swift-XRT afterglow detection
  75. GRB 211107B: Swift-XRT observations
  76. MeerLICHT follow-up of GRB 211106A
  77. GRB 211107B: Swift ToO observations
  78. GRB 211107B: Swift/BAT detection
  79. Fermi GBM Sub-Threshold Detection of GRB 211106A
  80. Konus-Wind detection of GRB 211106A
  81. GRB 211106A: Swift-XRT observations
  82. GRB 211106A: Swift ToO observations
  83. GRB 211106A: Swift/BAT-GUANO candidate arcminute localization of a short burst
  84. GRB 211105A: Swift/BAT-GUANO detection outside the coded FOV
  85. Swift Trigger 1082569 is probably not a GRB
  86. GRB 211024A: MITSuME Akeno optical observation
  87. GRB 211023B: MITSuME Akeno optical upper limits
  88. GRB 211024A: 1.3m DFOT observations
  89. IPN triangulation of GRB 211022A
  90. AMON NuEm-211020A: No Candidate Counterparts from Swift-XRT follow up observations
  91. GRB 211024A: Swift-XRT source 4 is not an afterglow.
  92. GRB 211024A: Possible afterglow candidate from GIT
  93. GRB 211024A: Swift-XRT observations
  94. GRB 211024A: Fermi GBM detection
  95. GRB 211018A: Swift-XRT observations
  96. GRB 211025A: Optical Afterglow Detection
  97. GRB 211024A: Swift ToO observations
  98. GRB 211024A: Swift/BAT-GUANO detection and candidate arcminute localization of a short burst
  99. GRB 211024B: Swift/UVOT detection
  100. Swift GRB 211025A: Global MASTER-Net observations report

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