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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"

21525 results found.

  1. GRB 220118A: Swift/UVOT Detection
  2. GRB 220118A: GIT optical observations
  3. GRB 220118A: Enhanced Swift-XRT position
  4. Swift GRB220118.50: Global MASTER-Net observations report
  5. GRB 220118A: MITSuME Akeno optical observation
  6. GRB 220117B: z-band limit
  7. Swift GRB 220118A: Global MASTER-Net observations report
  8. GRB 220118A: Swift detection of a burst with an optical counterpart
  9. GRB 220117A: MITSuME Akeno optical upper limits
  10. Fermi GBM Sub-Threshold Detection of GRB 220117A
  11. GRB 220117B: Swift-BAT refined analysis
  12. GRB 220117A: Swift-BAT refined analysis
  13. GRB 220117B: Swift/UVOT Upper Limits
  14. GRB 220117A: Swift/UVOT Upper Limits
  15. GRB 220117A: LCO Optical Observations
  16. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  17. GRB 220117B: Swift-XRT refined Analysis
  18. GRB 220117A: Swift-XRT refined Analysis
  19. GRB 220117B: Nanshan/NEXT optical upper limit
  20. GRB 220117B: MITSuME Akeno optical upper limits
  21. GRB 220117B: Enhanced Swift-XRT position
  22. GRB 220117A: Enhanced Swift-XRT position
  23. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  24. Swift GRB 220117A: Global MASTER-Net observations report
  25. Swift GRB 220117B: Global MASTER-Net observations report
  26. GRB 220117B: Swift detection of a burst
  27. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  28. GRB 220117A: Swift detection of a burst
  29. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  30. GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
  31. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  32. Konus-Wind detection of GRB 220101A
  33. Konus-Wind detection of GRB 220107A
  34. Confirmation of the X-ray afterglow of GRB 220107B
  35. GRB 220107A: 6m BTA spectroscopic redshift
  36. GRB 220108A: Swift/BAT-GUANO detection outside the coded FOV
  37. GRB 220101A: SAO RAS optical observations
  38. GRB 220107A: AbAO and Terskol optical observations
  39. GRB 220107B: MITSuME Akeno optical upper limits
  40. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  41. GRB 220107A: Nanshan/NEXT optical observations
  42. GRB 220107A: Swift/UVOT Detection
  43. GRB 220107A: MITSuME Akeno optical observation
  44. GRB 220107B: AstroSat CZTI detection
  45. GRB 220107B: Swift-XRT afterglow detection
  46. GRB 220107A: Swift-XRT afterglow detection
  47. GRB 220107B: Fermi-LAT detection
  48. GRB 220107A: AstroSat CZTI detection
  49. GRB 220107B: Tiled Swift observations
  50. GRB 220107A: Fermi GBM observations
  51. GRB 220107A: Swift ToO observations
  52. GRB 220107A: Swift/BAT-GUANO arcminute localization
  53. GRB 220101A: Tautenburg observations
  54. GRB 220101A: Continued Mondy optical observations
  55. GRB 220101A: Mondy optical observations
  56. GRB 220101A: 3rd LCO Optical Observation
  57. GRB 220101A: 2.2m CAHA (+CAFOS) first day optical detection
  58. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  59. GRB 220101A: 1.3m DFOT observations
  60. GRB 220101A: LCO Continued Optical Observations
  61. GRB 211229B: Fermi GBM observation
  62. GRB 211227A: Gemini South Optical Observations
  63. GRB 211229B: Swift/BAT-GUANO detection outside the coded FOV
  64. GRB 220101A: LCO Optical Observations
  65. GRB 220101A: Swift-BAT refined analysis
  66. GRB 220101A: OASDG optical observations
  67. GRB 220101A : Eiso equals the maximum isotropic GRB energy
  68. GRB 220101A: Fermi GBM Detection
  69. GRB 220101A: CAHA 2.2m/CAFOS detection
  70. GRB 220101A: Swift-XRT refined Analysis
  71. GRB 220101A: AGILE detection
  72. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  73. Swift GRB220101.22: Global MASTER-Net observations report
  74. GRB 220101: Swift/UVOT Detection
  75. GRB 220101A: Fermi-LAT detection
  76. GRB 220101A: Enhanced Swift-XRT position
  77. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  78. IPN triangulation of GRB 211219A
  79. GRB 211229A: Swift-XRT and UVOT observations
  80. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  81. GRB 211229A: Fermi GBM observation
  82. GRB 211229C: Swift/BAT-GUANO detection likely outside the coded FOV
  83. GRB 211229A: Swift ToO observations
  84. GRB 211229A: Swift/BAT-GUANO arcminute localization
  85. GRB 211227A: CALET Gamma-Ray Burst Monitor detection
  86. GRB 211225B: CALET Gamma-Ray Burst Monitor detection
  87. GRB 211227A: Swift/UVOT Upper Limits
  88. GRB 211227A: Swift-XRT refined Analysis
  89. GRB 211227A: Swift-BAT refined analysis
  90. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  91. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  92. GRB 211227A: Liverpool Telescope upper limits
  93. GRB 211227A: Enhanced Swift-XRT position
  94. GRB 211227A: LCO Optical Observations
  95. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  96. GRB 211227A: MAXI/GSC detection
  97. GRB 211227A: BOOTES-2/TELMA optical upper limit
  98. GRB 211221A: Swift/UVOT Upper Limits
  99. GRB 211227A: Swift detection of a burst
  100. Swift GRB211227.98: Global MASTER-Net observations report

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