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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"

19670 results found.

  1. GRB 220118A: Fermi GBM detection
  2. GRB 220118A: COATLI Optical Observations
  3. GRB 220117C: Swift/BAT-GUANO arcminute localization
  4. Swift currently in safe hold with science slews disabled
  5. GRB 220118A: Swift-BAT refined analysis
  6. GRB 220118A: Swift/UVOT Detection
  7. GRB 220118A: GIT optical observations
  8. GRB 220118A: Enhanced Swift-XRT position
  9. Swift GRB220118.50: Global MASTER-Net observations report
  10. GRB 220118A: MITSuME Akeno optical observation
  11. Swift GRB 220118A: Global MASTER-Net observations report
  12. GRB 220118A: Swift detection of a burst with an optical counterpart
  13. GRB 220117A: MITSuME Akeno optical upper limits
  14. Fermi GBM Sub-Threshold Detection of GRB 220117A
  15. GRB 220117B: Swift-BAT refined analysis
  16. GRB 220117A: Swift-BAT refined analysis
  17. GRB 220117B: Swift/UVOT Upper Limits
  18. GRB 220117A: Swift/UVOT Upper Limits
  19. GRB 220117A: LCO Optical Observations
  20. GRB 220117B: Swift-XRT refined Analysis
  21. GRB 220117A: Swift-XRT refined Analysis
  22. GRB 220117B: Nanshan/NEXT optical upper limit
  23. GRB 220117B: MITSuME Akeno optical upper limits
  24. GRB 220117B: Enhanced Swift-XRT position
  25. GRB 220117A: Enhanced Swift-XRT position
  26. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  27. Swift GRB 220117A: Global MASTER-Net observations report
  28. Swift GRB 220117B: Global MASTER-Net observations report
  29. GRB 220117B: Swift detection of a burst
  30. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  31. GRB 220117A: Swift detection of a burst
  32. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  33. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  34. Konus-Wind detection of GRB 220101A
  35. Konus-Wind detection of GRB 220107A
  36. Confirmation of the X-ray afterglow of GRB 220107B
  37. GRB 220107A: 6m BTA spectroscopic redshift
  38. GRB 220108A: Swift/BAT-GUANO detection outside the coded FOV
  39. GRB 220101A: SAO RAS optical observations
  40. GRB 220107A: AbAO and Terskol optical observations
  41. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  42. GRB 220107A: Nanshan/NEXT optical observations
  43. GRB 220107A: Swift/UVOT Detection
  44. GRB 220107A: MITSuME Akeno optical observation
  45. GRB 220107B: AstroSat CZTI detection
  46. GRB 220107B: Swift-XRT afterglow detection
  47. GRB 220107A: Swift-XRT afterglow detection
  48. GRB 220107B: Fermi-LAT detection
  49. GRB 220107A: AstroSat CZTI detection
  50. GRB 220107B: Tiled Swift observations
  51. GRB 220107A: Fermi GBM observations
  52. GRB 220107A: Swift ToO observations
  53. GRB 220107A: Swift/BAT-GUANO arcminute localization
  54. GRB 220101A: Tautenburg observations
  55. GRB 220101A: Continued Mondy optical observations
  56. GRB 220101A: Mondy optical observations
  57. GRB 220101A: 3rd LCO Optical Observation
  58. GRB 220101A: 2.2m CAHA (+CAFOS) first day optical detection
  59. GRB 220101A: 1.3m DFOT observations
  60. GRB 220101A: LCO Continued Optical Observations
  61. GRB 211229B: Fermi GBM observation
  62. GRB 211229B: Swift/BAT-GUANO detection outside the coded FOV
  63. GRB 220101A: LCO Optical Observations
  64. GRB 220101A: Swift-BAT refined analysis
  65. GRB 220101A: OASDG optical observations
  66. GRB 220101A : Eiso equals the maximum isotropic GRB energy
  67. GRB 220101A: Fermi GBM Detection
  68. GRB 220101A: CAHA 2.2m/CAFOS detection
  69. GRB 220101A: Swift-XRT refined Analysis
  70. GRB 220101A: AGILE detection
  71. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  72. Swift GRB220101.22: Global MASTER-Net observations report
  73. GRB 220101: Swift/UVOT Detection
  74. GRB 220101A: Fermi-LAT detection
  75. GRB 220101A: Enhanced Swift-XRT position
  76. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  77. IPN triangulation of GRB 211219A
  78. GRB 211229A: Swift-XRT and UVOT observations
  79. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  80. GRB 211229A: Fermi GBM observation
  81. GRB 211229C: Swift/BAT-GUANO detection likely outside the coded FOV
  82. GRB 211229A: Swift ToO observations
  83. GRB 211229A: Swift/BAT-GUANO arcminute localization
  84. GRB 211227A: CALET Gamma-Ray Burst Monitor detection
  85. GRB 211225B: CALET Gamma-Ray Burst Monitor detection
  86. GRB 211227A: Swift/UVOT Upper Limits
  87. GRB 211227A: Swift-XRT refined Analysis
  88. GRB 211227A: Swift-BAT refined analysis
  89. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  90. GRB 211227A: Enhanced Swift-XRT position
  91. GRB 211227A: LCO Optical Observations
  92. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  93. GRB 211227A: MAXI/GSC detection
  94. GRB 211227A: BOOTES-2/TELMA optical upper limit
  95. GRB 211221A: Swift/UVOT Upper Limits
  96. GRB 211227A: Swift detection of a burst
  97. Swift GRB211227.98: Global MASTER-Net observations report
  98. GRB 211226A: Swift/BAT-GUANO detection outside the coded FOV
  99. GRB 211225B: Swift-BAT refined analysis
  100. Swift GRB 211225B: Global MASTER-Net observations report

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