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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"

39463 results found.

  1. GRB 210822A: Detection by GRBAlpha
  2. GRB 210822A: GECAM refined analysis
  3. GRB 210820A: GROND observations
  4. Konus-Wind detection of GRB 210822A
  5. GRB 210822A: AstroSat CZTI detection
  6. GRB 210822A: NOT photometry and spectroscopy
  7. GRB 210822A: Swift-XRT refined Analysis
  8. Fermi trigger No 651306769: Global MASTER-Net observations report
  9. GRB 210822A: Swift-BAT refined analysis
  10. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  11. GRB 210822A: Fermi-LAT detection
  12. GRB 210820A: Swift/UVOT Detection
  13. Fermi GRB 210822B: Global MASTER-Net observations report
  14. GRB 210822A: Nanshan/NEXT optical observations
  15. GRB 210822B: Fermi GBM Final Real-time Localization
  16. GRB 210822A: Enhanced Swift-XRT position
  17. Swift GRB 210822A: Global MASTER-Net observations report
  18. GRB 210822A: RATIR Optical Detections
  19. GRB 210822A: KAIT Optical Afterglow Confirmation
  20. GRB 210822A: GECAM detection
  21. GRB 210822A: Swift detection of a burst with an optical afterglow
  22. Fermi GRB 210821A: Global MASTER-Net observations report
  23. GRB 210820A: Swift-BAT refined analysis
  24. GRB 210820A: LT optical upper limit
  25. GRB 210820A: LCO Optical Upper Limit
  26. GRB 210820A: RATIR Optical Detections
  27. GRB 210821A: Fermi GBM Final Real-time Localization
  28. GRB 210820A: NOT optical upper limit
  29. GRB 210820A: Nanshan/NEXT optical upper limit
  30. GRB 210820A: Swift-XRT refined Analysis
  31. GRB 210820A: Enhanced Swift-XRT position
  32. Swift GRB 210820A: Global MASTER-Net observations report
  33. GRB 210820B: Fermi GBM Final Localization
  34. GRB 210820A: Swift detection of a burst with an optical counterpart
  35. Fermi trigger No 651110719: Global MASTER-Net observations report
  36. Swift GRB210818.68: Global MASTER-Net observations report
  37. Swift GRB 210818A: Global MASTER-Net observations report
  38. GRB 210818A: Swift-XRT refined Analysis
  39. GRB 210818A: Swift-BAT refined analysis
  40. GRB 210726A: VLA radio afterglow detection
  41. Konus-Wind detection of GRB 210818A
  42. Swift Trigger 1069242 is Cyg X-1
  43. GRB 210818A: AstroSat CZTI detection
  44. GRB 210818A: AGILE detection
  45. GRB 210818A: Enhanced Swift-XRT position
  46. GRB 210818A: Swift detection of a burst with an optical counterpart
  47. IceCube-210811A: Upper limits from Fermi-GBM Observations
  48. GRB 210815A: BALROG localization (Fermi Trigger 650687034 / GRB 210815100)
  49. GRB 210815A: Fermi GBM Final Real-time Localization
  50. Fermi trigger No 650687034: Global MASTER-Net observations report
  51. GRB 210812A is consistent with being a lensed GRB
  52. GRB 210712A: Fermi GBM observation
  53. GRB 210813A: BALROG localization (Fermi Trigger 650508868 / GRB 210813038)
  54. Fermi GRB 210813A: Global MASTER-Net observations report
  55. GRB 210813A: Fermi GBM Final Real-time Localization
  56. Fermi-LAT Gamma-ray Observations of IceCube-210811A
  57. Retraction of Fermi GBM GCN 30630 and GCN 30632
  58. GRB 210807A: continued Assy, AbAO and Mondy observations
  59. Fermi GRB 210812A: Global MASTER-Net observations report
  60. GRB 210812B: Fermi GBM Final Real-time Localization
  61. GRB 210812A: BALROG localization (Fermi Trigger 650479626 / GRB 210812699)
  62. GRB 210812A: Fermi GBM Final Real-time Localization
  63. GRB 080102A: Fermi GBM Final Real-time Localization
  64. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  65. GRB 080101A: Fermi GBM Final Real-time Localization
  66. GRB 210730A: Tautenburg observations
  67. GRB 210807A: Tautenburg observations
  68. IceCube-210811A - IceCube observation of a high-energy neutrino candidate track-like event
  69. IceCube Alert 210811.09: Global MASTER-Net observations report
  70. GRB 210807C: Swift-BAT refined analysis
  71. GRB 210807A: Detection by GRBAlpha
  72. GRB 210807A: Swift-BAT refined analysis
  73. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  74. GRB 210807C: Swift-XRT refined Analysis
  75. GRB 210807C: Fermi GBM detection
  76. GRB 210807C: Swift/UVOT Upper Limits
  77. GRB 210807A: Swift/UVOT Detection
  78. GRB 210807A: Swift-XRT refined Analysis
  79. GRB 210807A: correction to the GCN Circ. #30614 Assy optical observations
  80. GRB 210807C: Enhanced Swift-XRT position
  81. GRB 210610B: Assy optical observations
  82. Swift GRB210807.74: Global MASTER-Net observations report
  83. Fermi GRB 210807C: Global MASTER-Net observations report
  84. Swift GRB210807.96: Global MASTER-Net observations report
  85. GRB 210807C: Swift detection of a burst
  86. GRB 210807C: Fermi GBM Final Real-time Localization
  87. Fermi GRB 210807B: Global MASTER-Net observations report
  88. Swift GRB 210807A: Global MASTER-Net observations report
  89. Swift GRB210807.79: Global MASTER-Net observations report
  90. Swift GRB210807.78: Global MASTER-Net observations report
  91. Fermi trigger No 650046564: Global MASTER-Net observations report
  92. GRB 210807A: Enhanced Swift-XRT position
  93. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  94. GRB 210807B: Fermi GBM Final Real-time Localization
  95. GRB 210807A: Swift detection of a burst with an optical counterpart
  96. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 August 5
  97. IPN Triangulation of a bright burst from SGR 1935+2154
  98. Fermi trigger No 649814537: Global MASTER-Net observations report
  99. GRB 210802A: MITSuME Okayama optical upper limits
  100. GRB 210803A: Fermi GBM observation

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