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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"

26119 results found.

  1. GRB 211221A: No V & R detection, KAO telescope
  2. GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  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. GRB 220117B: z-band limit
  12. Swift GRB 220118A: Global MASTER-Net observations report
  13. GRB 220118A: Swift detection of a burst with an optical counterpart
  14. GRB 220117A: MITSuME Akeno optical upper limits
  15. Fermi GBM Sub-Threshold Detection of GRB 220117A
  16. GRB 220117B: Swift-BAT refined analysis
  17. GRB 220117A: Swift-BAT refined analysis
  18. GRB 220117B: Swift/UVOT Upper Limits
  19. GRB 220117A: Swift/UVOT Upper Limits
  20. GRB 220117A: LCO Optical Observations
  21. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  22. GRB 220117B: Swift-XRT refined Analysis
  23. GRB 220117A: Swift-XRT refined Analysis
  24. GRB 220117B: Nanshan/NEXT optical upper limit
  25. GRB 220117B: MITSuME Akeno optical upper limits
  26. GRB 220117B: Enhanced Swift-XRT position
  27. GRB 220117A: Enhanced Swift-XRT position
  28. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  29. Swift GRB 220117A: Global MASTER-Net observations report
  30. Swift GRB 220117B: Global MASTER-Net observations report
  31. GRB 220117B: Swift detection of a burst
  32. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  33. GRB 220117A: Swift detection of a burst
  34. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  35. GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
  36. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  37. Konus-Wind detection of GRB 220101A
  38. GRB 220107A: SAO RAS optical observations
  39. Konus-Wind detection of GRB 220107A
  40. Confirmation of the X-ray afterglow of GRB 220107B
  41. GRB 220107A: further SAO RAS optical observations
  42. GRB 220101A: Additional Liverpool telescope photometry
  43. GRB 220107A: 6m BTA spectroscopic redshift
  44. GRB 220107A: SAO RAS optical observations
  45. GRB 220108A: Swift/BAT-GUANO detection outside the coded FOV
  46. GRB 220101A: SAO RAS optical observations
  47. GRB 220107A: AbAO and Terskol optical observations
  48. GRB 220107B: MITSuME Akeno optical upper limits
  49. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  50. GRB 220107A: Nanshan/NEXT optical observations
  51. GRB 220107A: Swift/UVOT Detection
  52. GRB 220107A: MITSuME Akeno optical observation
  53. GRB 220107B: AstroSat CZTI detection
  54. GRB 220107B: Swift-XRT afterglow detection
  55. GRB 220107A: Swift-XRT afterglow detection
  56. GRB 220107B: Fermi-LAT detection
  57. GRB 220107A: AstroSat CZTI detection
  58. GRB 220107B: Tiled Swift observations
  59. GRB 220107A: Fermi GBM observations
  60. GRB 220107A: Swift ToO observations
  61. GRB 220107A: Swift/BAT-GUANO arcminute localization
  62. GRB 220101A: Tautenburg observations
  63. GRB 220101A: Continued Mondy optical observations
  64. GRB 220101A: further TNG NIR observations
  65. GRB 220101A: continued 1.3m DFOT Optical Observations
  66. GRB 220101A: Mondy optical observations
  67. GRB 220101A: 3rd LCO Optical Observation
  68. GRB 220101A: 2.2m CAHA (+CAFOS) first day optical detection
  69. GRB 220101A: iTelescope optical observations
  70. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  71. GRB 220101A: 1.3m DFOT observations
  72. GRB 220101A: LCO Continued Optical Observations
  73. GRB 211229B: Fermi GBM observation
  74. GRB 211227A: Gemini South Optical Observations
  75. GRB 211229B: Swift/BAT-GUANO detection outside the coded FOV
  76. GRB 220101A: TNG NIR afterglow detection
  77. GRB 220101A: LCO Optical Observations
  78. GRB 220101A: Swift-BAT refined analysis
  79. GRB 220101A: GMG observation (2nd epoch)
  80. GRB 220101A: OASDG optical observations
  81. GRB 220101A : Eiso equals the maximum isotropic GRB energy
  82. GRB 220101A: GMG observation
  83. GRB 220101A: Asiago spectroscopic and photometric detection
  84. GRB220101A: optical afterglow detection from Konkoly Observatory
  85. GRB 220101A: Fermi GBM Detection
  86. GRB 220101A: NOT redshift confirmation
  87. GRB 220101A: CAHA 2.2m/CAFOS detection
  88. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  89. GRB 220101A: THO optical observations
  90. GRB 220101A: Swift-XRT refined Analysis
  91. GRB 220101A: AGILE detection
  92. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  93. Swift GRB220101.22: Global MASTER-Net observations report
  94. GRB 220101: Swift/UVOT Detection
  95. GRB 220101A: Fermi-LAT detection
  96. GRB 220101A: Enhanced Swift-XRT position
  97. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  98. IPN triangulation of GRB 211219A
  99. GRB 211229A: Swift-XRT and UVOT observations
  100. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation

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