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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. GRB 210222B: Swift-XRT refined Analysis
  2. GRB 210222B: Swift/UVOT Detection
  3. GRB 210222B: KAIT Optical Upper Limit
  4. GRB 210218A: Swift/UVOT observations
  5. GRB 210217A: Swift/UVOT Detection
  6. GRB 210222B: MASTER OT observation
  7. GRB 210222B: GOTO confirmation of afterglow detection
  8. GRB210222B: LCO Optical Afterglow Detection
  9. GRB210222B: BOOTES-1 optical afterglow detection
  10. GRB 210222B: Swift detection of a burst with an optical counterpart
  11. Swift GRB210222.94: Global MASTER-Net observations report
  12. GRB 210218A: Swift-XRT observations
  13. GRB 210212A: Lowell Discovery Telescope observations
  14. GRB 210217A: 1.3m DFOT optical detection
  15. GRB 210217A: Swift-XRT refined Analysis
  16. GRB 210218A: Swift-BAT refined analysis
  17. Fermi GBM Sub-Threshold Detection of GRB 210217A
  18. GRB 210217A: Liverpool Telescope First Hour Observations
  19. GRB 210217A: Swift-BAT refined analysis
  20. GRB 210217A: KAIT Optical Observations
  21. GRB 210218A: MITSuME Akeno optical upper limits
  22. GRB 210218A： GWAC-F60A optical upper limit
  23. GRB 210218A: NEXT optical upper limit
  24. GRB 210218A: Swift detection of a burst
  25. GRB 210205A: observations with the 3.6m DOT, a potential dark burst?
  26. GRB 210217A: Enhanced Swift-XRT position
  27. Fermi/GBM observation of a burst from SGR 1830-0645
  28. GRB 210217A: NEXT early optical afterglow observations
  29. GRB 210217A: Swift detection of a burst with an optical counterpart
  30. GRB 210210A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  31. Swift Trigger 1033144: Detection of SGR 1830-0645
  32. GRB 210212B: Swift ToO observations
  33. IPN triangulation of GRB 210212B (consistent with ZTF21aakruew/AT2021cwd)
  34. GRB 210212A: 1.3m DFOT Optical upper limit
  35. GRB 210212A: Gemini South optical observations
  36. Swift Trigger 1032350: Detection of SGR 1830-0645
  37. GRB 210212A: Possible host galaxy counterpart with the NOT
  38. Swift GRB 210212A: Global MASTER-Net observations report
  39. GRB 210212A: MITSuME Akeno optical upper limits
  40. GRB 210212A: Swift-XRT refined Analysis
  41. GRB 210212A: BOOTES-4/MET optical upper limit
  42. GRB 210212A: Swift/UVOT Upper Limits
  43. GRB 210212A: Swift-BAT refined analysis
  44. GRB 210212A: Enhanced Swift-XRT position
  45. GRB 210212A: Swift detection of a burst
  46. GRB 210207B: GECAM detection
  47. GRB 210211A: Swift/UVOT Detection
  48. GRB 210211A: Swift-XRT refined Analysis
  49. GRB 210211A: Swift-BAT refined analysis
  50. GRB 210211A: Fermi GBM observation
  51. Swift-XRT observations of IceCube-210210A
  52. GRB 210209A: Swift-BAT refined analysis
  53. GRB 210211A: Enhanced Swift-XRT position
  54. GRB 210211A: MASTER optical observation of REM OT
  55. GRB 210211A: Swift detection of a burst
  56. Swift GRB210211.36: Global MASTER-Net observations report
  57. GRB 210210A: Swift-BAT refined analysis
  58. GRB 210209A: BOOTES-4/MET optical upper limit
  59. GRB 210210A: LCO Optical Afterglow Detection
  60. Swift GRB 210209A: Global MASTER-Net observations report
  61. GRB 210210A: Swift/UVOT Detection
  62. GRB 210209A: MITSuME Akeno optical upper limits
  63. GRB 210209A: Swift/UVOT Upper Limits
  64. GRB 210210A: Swift-XRT refined Analysis
  65. GRB 210210A: Redshift from OSIRIS/GTC
  66. GRB 210209A: Swift-XRT refined Analysis
  67. GRB 210210A: Enhanced Swift-XRT position
  68. GRB 210210A: MASTER afterglow observation
  69. Swift GRB 210210A: Global MASTER-Net observations report
  70. GRB 210210A: Swift detection of a burst with an optical counterpart
  71. GRB 210209A: Enhanced Swift-XRT position
  72. GRB 210209A: Swift detection of a burst
  73. GRB 210207B: Continued LCO Observations
  74. GRB 210207B: AstroSat CZTI detection
  75. GRB 210207B: Swift/UVOT Detection
  76. GRB 210207B: Swift-BAT refined analysis
  77. GRB 210207B: Insight-HXMT/HE detection
  78. GRB 210207B: LCO Optical Afterglow Detection
  79. GRB 210207B: KAIT Optical Observations
  80. GRB 210207B: AGILE observations
  81. GRB 210207B: Swift-XRT refined Analysis
  82. Konus-Wind detection of GRB 210207B
  83. GRB 210207B: Enhanced Swift-XRT position
  84. GRB 210207B: optical detection with 3.6m Devasthal Optical Telescope
  85. GRB 210207B: Swift detection of a burst with a bright optical counterpart
  86. GRB 210204A / ZTF21aagwbjr: Swift-XRT observations
  87. GRB 210204A: Swift ToO observations
  88. GRB 210205A: Swift-BAT refined analysis
  89. IPN triangulation of GRB 210204A
  90. GRB 210205A: Swift-XRT refined Analysis
  91. GRB 210205A: MITSuME Ishigaki optical observation
  92. GRB 210205A: Swift/UVOT Upper Limits
  93. Swift GRB 210205A: Global MASTER-Net observations report
  94. GRB 210205A: BOOTES-4/MET optical upper limit
  95. GRB 210205A: Enhanced Swift-XRT position
  96. GRB 210205A: Swift detection of a burst
  97. GRB 210202A: Fermi-LAT detection
  98. Fermi GBM Observations of SGR J1935+2154
  99. GRB 140330A: Swift-XRT refined Analysis
  100. GRB 140320B: Swift-XRT refined Analysis

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