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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"

27957 results found.

  1. GRB 210909A: Fermi GBM Final Real-time Localization
  2. GRB 210905A: Swift/UVOT Upper Limits
  3. GRB 210905A: ATCA detection
  4. GRB 210905A: ALMA detection
  5. GRB 210905A: AstroSat CZTI detection
  6. GRB 210905A, GROND observations
  7. Konus-Wind detection of GRB 210905A
  8. Fermi GBM Sub-Threshold Detection of GRB 210905A
  9. GRB 210905A: Swift-XRT refined Analysis
  10. GRB 210827B: GECAM detection
  11. GRB 210905A: DECam Detection
  12. GRB 210905A: REM NIR afterglow detection
  13. GRB 210905A: VLT/X-shooter spectroscopic redshift
  14. GRB 210905A: Continued LCO Optical Observations
  15. GRB 210905A: LCO Optical Detection
  16. GRB 210905A: Enhanced Swift-XRT position
  17. GRB 210901A: Swift/UVOT Upper Limits
  18. Swift GRB 210905A: Global MASTER-Net observations report
  19. GRB 210905A: Swift detection of a burst
  20. GRB 210904A: Fermi GBM Final Real-time Localization
  21. Swift GRB210903.59: Global MASTER-Net observations report
  22. Swift GRB210903.58: Global MASTER-Net observations report
  23. Swift GRB210903.58: Global MASTER-Net observations report
  24. GRB 210903C: Fermi GBM Final Real-time Localization
  25. GRB 210901A: GROND observations
  26. GRB 210903B: Fermi GBM Final Localization
  27. Fermi GBM observation of a burst from SGR J1555.2-5402
  28. GRB 210903A: Fermi GBM Final Real-time Localization
  29. GRB 210901A: Swift-XRT refined Analysis
  30. GRB 210901A: Swift-BAT refined analysis
  31. GRB 210901A: Enhanced Swift-XRT position
  32. GRB 210901A: LCO Optical Upper Limit
  33. Swift GRB 210901A: Global MASTER-Net observations report
  34. GRB 210901A: Swift detection of a burst
  35. GRB 210827A: further Swift-XRT observations
  36. GRB 210822A: CALET Gamma-Ray Burst Monitor detection
  37. GRB 210827A: Swift/UVOT Upper Limits
  38. GRB 210827A: BOOTES-5/JGT optical upper limit
  39. GRB 210827A: Fermi GBM Observation
  40. GRB 210826A: AstroSat CZTI detection
  41. GRB 210827A: Swift-XRT observations
  42. GRB 210827A: Swift ToO observations
  43. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  44. GRB 210820A: CAHA 2.2m Optical Detection
  45. GRB 210824A: Swift/UVOT Upper Limits
  46. GRB 210826A: Swift/UVOT Upper Limits
  47. POLAR detection of a SGR-like burst
  48. GRB 210827B: Fermi GBM Final Real-time Localization
  49. GRB 210826A: Swift-XRT observations
  50. GRB 210827A: Fermi GBM Final Real-time Localization
  51. GRB 210822A: CAHA 2.2m observations
  52. GRB 210824A: Swift-BAT refined analysis
  53. GRB 210826A: Fermi-LAT detection
  54. GRB 210826A: Tiled Swift observations
  55. GRB 210826A: Fermi GBM Final Real-time Localization
  56. Swift GRB210825.29: Global MASTER-Net observations report
  57. GRB 210822A: VLA detection
  58. Swift detection of an outburst from SGR Swift J1555.2-5402
  59. GRB 210822A: Swift/UVOT Detection
  60. Swift GRB 210824A: Global MASTER-Net observations report
  61. GRB 210824A: BOOTES-5/JGT optical upper limit
  62. GRB 210824A: Fermi GBM Observation
  63. GRB 210824A: Nanshan/NEXT optical upper limit
  64. GRB 210824A: Swift-XRT refined Analysis
  65. GRB 210822A: GROND observations
  66. GRB 210824A: Enhanced Swift-XRT position
  67. GRB 210824A: Swift detection of a burst
  68. GRB 210824A: Fermi GBM Final Real-time Localization
  69. GRB 210822A: Detection by GRBAlpha
  70. GRB 210822A: GECAM refined analysis
  71. GRB 210820A: GROND observations
  72. Konus-Wind detection of GRB 210822A
  73. GRB 210822A: AstroSat CZTI detection
  74. GRB 210822A: Swift-XRT refined Analysis
  75. GRB 210822A: Swift-BAT refined analysis
  76. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  77. GRB 210822A: Fermi-LAT detection
  78. GRB 210820A: Swift/UVOT Detection
  79. GRB 210822B: Fermi GBM Final Real-time Localization
  80. GRB 210822A: Enhanced Swift-XRT position
  81. Swift GRB 210822A: Global MASTER-Net observations report
  82. GRB 210822A: KAIT Optical Afterglow Confirmation
  83. GRB 210822A: GECAM detection
  84. GRB 210822A: Swift detection of a burst with an optical afterglow
  85. GRB 210820A: Swift-BAT refined analysis
  86. GRB 210820A: LT optical upper limit
  87. GRB 210820A: LCO Optical Upper Limit
  88. GRB 210820A: RATIR Optical Detections
  89. GRB 210821A: Fermi GBM Final Real-time Localization
  90. GRB 210820A: NOT optical upper limit
  91. GRB 210820A: Nanshan/NEXT optical upper limit
  92. GRB 210820A: Swift-XRT refined Analysis
  93. GRB 210820A: Enhanced Swift-XRT position
  94. Swift GRB 210820A: Global MASTER-Net observations report
  95. GRB 210820B: Fermi GBM Final Localization
  96. GRB 210820A: Swift detection of a burst with an optical counterpart
  97. Swift GRB210818.68: Global MASTER-Net observations report
  98. Swift GRB 210818A: Global MASTER-Net observations report
  99. GRB 210818A: Swift-XRT refined Analysis
  100. GRB 210818A: Swift-BAT refined analysis

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