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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"

27814 results found.

  1. ​GRB 221009A: Multi-color detection of the optical
  2. GRB 221009A: Fermi-LAT refined analysis
  3. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  4. GRB 221009: Swift/UVOT Detection
  5. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  6. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  7. GRB 221009A/Swift J1913.1+1946: AMI-LA observations
  8. GRB 221009A: REM optical and NIR detection of the afterglow
  9. GRB 221009A: Swift-XRT refined Analysis
  10. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  11. Swift J1913.1+1946: Early Optical Photometry
  12. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  13. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  14. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  15. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  16. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  17. GRB 221009A: Fermi GBM observation
  18. IPN triangulation of extremely bright GRB 221009A
  19. Swift J1913.1+1946: Optical photometry
  20. Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
  21. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  22. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  23. GRB 221009A: Swift detected transient may be GRB
  24. Swift GRB221009.59: Global MASTER-Net OT detection
  25. GRB 221008A: Swift-XRT observations
  26. Swift J1913.1+1946 a new bright hard X-ray and optical transient
  27. GRB 221008A: Tiled Swift observations
  28. GRB 221008A: MAXI/GSC detection
  29. GRB 220915A: Detection by GRBAlpha
  30. GRB 221006A: Swift-XRT observations
  31. GRB 221006A: Tiled Swift observations
  32. GRB 221006A: MAXI/GSC detection
  33. GRB 220930A: MITSuME Akeno optical upper limits
  34. GRB 220912A: Detection by VZLUSAT-2
  35. GRB220927A: Detection by GRBAlpha
  36. GRB 220921A: ATCA detection of radio counterpart
  37. GRB 220930A: AbAO Optical Upper Limit
  38. Konus-Wind detection of GRB 220930A
  39. GRB 220930A: AstroSat CZTI detection
  40. GRB 220930A: Swift-BAT refined analysis
  41. GRB 220930A: Swift-XRT refined Analysis
  42. GRB 220930A: LCOGT Optical Upper Limits
  43. GRB 220930A: Swift/UVOT Upper Limits
  44. GRB 220930A: Enhanced Swift-XRT position
  45. Swift GRB 220930A: Global MASTER-Net observations report
  46. GRB 220930A: BOOTES-5/JGT early optical upper limit
  47. GRB 220930A: Prompt enhanced Swift-XRT position
  48. GRB 220930A: COATLI Upper Limits
  49. GRB 220930A: Swift detection of a burst
  50. Konus-Wind detection of GRB 220927A
  51. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  52. IPN triangulation of GRB 220927A (long)
  53. GRB 220921A: LCOGT Optical Observations
  54. GRB 220927A: Fermi GBM Final Localization
  55. GRB 220924A: Fermi GBM detection
  56. Ultra-long GRB 220525B: Konus-Wind and Fermi-GBM detection
  57. Swift Trigger 1125354 (GRB 220926A) is not a GRB
  58. Swift GRB220926.34: Global MASTER-Net observations report
  59. Swift GRB 220926A: Global MASTER-Net observations report
  60. GRB 220926A: Swift detection of a burst
  61. GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
  62. GRB 220925A: Fermi GBM Final Real-time Localization
  63. GRB 220924A: Fermi GBM Final Real-time Localization
  64. Swift GRB220923.47: Global MASTER-Net observations report
  65. GRB 220921A: ALMA detection
  66. GRB 220921A: DDOTI Detection of the Afterglow
  67. Konus-Wind detection of GRB 220921A
  68. GRB 220921A: Fermi GBM detection
  69. GRB 220921A: MeerLICHT afterglow observations
  70. GRB 220921A: Swift-XRT Observations
  71. GRB 220921A: MASTER OT inside Fermi-LAT error-box
  72. GRB 220921A: Fermi-LAT detection
  73. GRB 220921A: Tiled Swift observations
  74. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  75. IceCube-220918A - IceCube observation of a high-energy neutrino candidate track-like event
  76. IceCube-220907A: No significant detection in HAWC
  77. GRB 220909A: Fermi GBM observation
  78. Konus-Wind detection of GRB 220910A
  79. GRB 220910B: Fermi GBM Final Localization
  80. IPN triangulation of GRB 220910A (bright/long)
  81. GRB 220912A: AstroSat CZTI detection
  82. GRB 220831A: DECam optical counterpart follow-up
  83. GRB 220909A: Swift-XRT observations
  84. GRB 220912A: Fermi GBM Final Real-time Localization
  85. IPN triangulation of GRB 220905A
  86. GRB 220909A: Swift ToO observations
  87. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
  88. GRB 220910A: AstroSat CZTI detection
  89. GRB 220910A: AGILE detection
  90. GRB 220909A: Fermi GBM Final Real-time Localization
  91. GRB 220907A: Swift-BAT refined analysis
  92. GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
  93. IPN triangulation of GRB 220903A (long)
  94. GRB 220907A: Fermi GBM observation
  95. GRB 220907A: Nanshan/NEXT optical upper limits
  96. GRB 220907A: Swift/UVOT Upper Limits
  97. GRB 220907A: Swift-XRT refined Analysis
  98. GRB 220831A: ATCA 5/9 GHz radio observations
  99. GRB 220907A: Swift-XRT position
  100. GRB 220907A: Swift detection of a burst

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