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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"

21135 results found.

  1. GRB 210410A: RATIR Optical and NIR Observations
  2. Fermi GRB 210410A: Global MASTER-Net observations report
  3. GRB 210406A: Swift ToO observations
  4. GRB 210406A: Mondy optical upper limit
  5. Integral GRB210406.72: Global MASTER-Net observations report
  6. GRB 210402A: Swift/UVOT Upper Limits
  7. GRB 210402A: Further NOT optical observations
  8. GRB 210207B: Prompt and very late time observations with HCT.
  9. GRB 210402A: NOT optical afterglow candidate
  10. Fermi trigger No 639199407: Global MASTER-Net observations report
  11. GRB 210402A: LBT observations
  12. Swift GRB210403.35: Global MASTER-Net observations report
  13. GRB 210402A: Montarrenti Observatory upper limit
  14. GRB 210402A: NOT optical upper limits
  15. GRB 210402A: Swift detection of a burst
  16. Fermi trigger No 639093861: Global MASTER-Net observations report
  17. Swift GRB210402.92: Global MASTER-Net observations report
  18. Fermi GRB 210401A: Global MASTER-Net observations report
  19. GRB 210330A: MASTER optical observation
  20. Fermi trigger No 638414549: Global MASTER-Net observations report
  21. GRB 210321A: OSN Upper Limit
  22. GRB 210323A: MASTER optical observation
  23. Fermi GRB 210324C: Global MASTER-Net observations report
  24. Fermi GRB 210324B: Global MASTER-Net observations report
  25. GRB 210323A: Gemini-North Optical Source Detection
  26. Short GRB 210323A: GTC Observations
  27. GRB 210312B: OSN Afterglow Observations
  28. GRB 210323B: Swift ToO observations
  29. GRB 210323A: Swift/UVOT Upper Limits
  30. GRB 210323A: Mondy optical observations, counterpart detection
  31. GRB 210318A: Swift/UVOT Upper Limits
  32. GRB 210323A: NOT optical afterglow candidate
  33. Swift GRB 210323A: Global MASTER-Net observations report
  34. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  35. GRB 210323A: Nanshan/NEXT optical upper limit
  36. GRB 210321A: Swift/UVOT Detection
  37. GRB 210318B: Swift/UVOT Upper Limits
  38. IceCube Alert 210322.11: Global MASTER-Net observations report
  39. IceCube 135113_19489408.amon: Swift-XRT observations
  40. GRB 210321A: Mondy optical observations
  41. GRB 210321A: NOT optical afterglow detection and redshift limit
  42. GRB 210321A: MASTER optical observation
  43. MAXI GRB210320.89: Global MASTER-Net observations report
  44. GRB 210321A: DDOTI Afterglow Confirmation
  45. GRB 210321A: Swift/UVOT Detection
  46. GRB 210321A: Swift-XRT observations
  47. GRB 201216C: VIRT optical observations
  48. Swift GRB210318.13: Global MASTER-Net observations report
  49. Fermi trigger No 637729731: Global MASTER-Net observations report
  50. Swift GRB 210318A: Global MASTER-Net observations report
  51. Fermi GRB 210317A: Global MASTER-Net observations report
  52. Fermi trigger No 637521056: Global MASTER-Net observations report
  53. GRB 210312B: Redshift from OSIRIS/GTC
  54. GRB 210306A: HCT optical upper limit
  55. GRB 210312B: MASTER OT confirmation
  56. Integral GRB210312.87: Global MASTER-Net observations report
  57. Fermi GRB 210312A: Global MASTER-Net observations report
  58. GRB 210306A: LBT observations
  59. GRB 210306A: Tautenburg observations
  60. GRB 171205A: Continued ATCA observations
  61. Fermi trigger No 637027080: Global MASTER-Net observations report
  62. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  63. GRB 210306A: Swift/UVOT Detection
  64. GRB 210306A: continued Mondy optical observations
  65. GRB 210308A: Mondy and AbAO optical observations
  66. Fermi trigger No 636926765: Global MASTER-Net observations report
  67. GRB 210308A: Swift/UVOT Detection
  68. GRB 210307A: Swift/UVOT Upper Limits
  69. Swift GRB 210308A: Global MASTER-Net observations report
  70. GRB 210308A: Nanshan/NEXT optical upper limits
  71. GRB 210306A: continued Mondy optical observations
  72. GRB 210306A: 1.3m DFOT observations
  73. GRB 210306A: Mondy optical observations
  74. GRB 210305A: Swift/UVOT Upper Limits
  75. Swift GRB210307.36: Global MASTER-Net observations report
  76. GRB 210306A: NEXT optical observations
  77. Swift GRB 210306A: Global MASTER-Net observations report
  78. GRB 210306A: Tautenburg observations
  79. GRB 210306A: iTelescope T24 optical observations
  80. GRB 210306A: iTelescope optical afterglow observations
  81. GRB 210306A: DDOTI Afterglow Confirmation
  82. Swift GRB 210305A: Global MASTER-Net observations report
  83. Fermi trigger No 636459103: Global MASTER-Net observations report
  84. GRB 210217A: 3.6m DOT optical observations
  85. GRB 210226A: Swift/UVOT Upper Limits
  86. Fermi trigger No 636187116: Global MASTER-Net observations report
  87. Fermi trigger No 636168178: Global MASTER-Net observations report
  88. Integral GRB210227.20: Global MASTER-Net observations report
  89. Integral GRB210227.20: Global MASTER-Net observations report
  90. Integral GRB210227.19: Global MASTER-Net observations report
  91. GRB 210217A: Mondy optical observations
  92. GRB 210226A: KAIT Optical Upper Limit
  93. Swift GRB 210226A: Global MASTER-Net observations report
  94. GRB 210218A: Swift-XRT confirmation of afterglow
  95. GRB 210222B: 1.3m DFOT Optical upper limit
  96. GRB 210222B: REM observations of the optical/NIR afterglow
  97. Fermi trigger No 635922820: Global MASTER-Net observations report
  98. GRB 210222B: Zeiss-1000 of Koshka observatory, optical observations
  99. GRB 210222B: Swift/UVOT Detection
  100. GRB 210218A: Swift/UVOT observations

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