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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 210419A: Swift-XRT refined Analysis
  2. GRB 210419C: Swift detection of a burst
  3. Swift GRB 210419A: Global MASTER-Net observations report
  4. GRB 210419A: Enhanced Swift-XRT position
  5. GRB 210419A: LCO Optical Upper Limit
  6. GRB 210419A: Swift detection of a burst
  7. GRB 210413B: Swift-XRT observations
  8. GRB 210413B: LOAO optical upper limit
  9. GRB 210411C: A very significant early X-ray afterglow
  10. GRB 210413B: Swift ToO observations
  11. GRB 210413B: Swift/BAT detection and probable localization of a short burst
  12. GRB 210410A: AstroSat CZTI detection
  13. GRB 210410A: A twin of short GRB 090510 with complementary observations
  14. GRB 210410A: Swift/UVOT Upper Limits (revision)
  15. GRB 210411C: Swift/UVOT Detection
  16. GRB 210411C: Swift-BAT refined analysis
  17. GRB 210411C: Chilescope optical observations
  18. GRB 210411C: Swift-XRT refined Analysis
  19. Swift GRB 210411C: Global MASTER-Net observations report
  20. GRB 210411C: BOOTES-4/MET optical upper limit
  21. GRB 210411C: LCO Optical Afterglow Candidate
  22. GRB 210411C: Enhanced Swift-XRT position
  23. GRB 210406A: 10.4m GTC follow-up observation
  24. Konus-Wind detection of GRB 210410A
  25. GRB 210411C: Swift detection of a burst with an optical counterpart
  26. GRB 210410A: Swift-BAT refined analysis
  27. GRB 210410A: Swift-XRT refined Analysis
  28. GRB 210410A: Fermi GBM detection
  29. GRB 210410A: Swift/UVOT Upper Limits
  30. GRB 210406A: Swift-XRT observations
  31. GRB 210410A: RATIR Optical and NIR Observations
  32. GRB 210410A: AGILE detection of a burst
  33. GRB 210410A: Fermi-LAT detection
  34. GRB210410A: Candidate optical afterglow by Ondrejov D50
  35. GRB 210410A: Swift XRT localization
  36. Swift Triggers 1042031 and 1042032 are not astrophysical events
  37. GRB 210406A: Swift ToO observations
  38. GRB 210402A: MASTER prompt and follow up optical observation
  39. GRB 210402A: Swift/UVOT Upper Limits
  40. GRB 210402A: Fermi GBM detection
  41. GRB 210402A: Swift-BAT refined analysis
  42. GRB 210207B: Prompt and very late time observations with HCT.
  43. GRB 210402A: NOT optical afterglow candidate
  44. GRB 210402A: BOOTES-network early optical upper limit
  45. GRB 210403A: Swift-BAT refined analysis
  46. GRB 210402A: LBT observations
  47. GRB 210402A: DDOTI Upper Limits
  48. Swift GRB210403.35: Global MASTER-Net observations report
  49. GRB 210402A: Swift-XRT refined Analysis
  50. GRB 210403A: Swift detection of a burst
  51. GRB 210402A: Montarrenti Observatory upper limit
  52. GRB 210402A: NOT optical upper limits
  53. GRB 210402A: Swift detection of a burst
  54. Swift GRB210402.92: Global MASTER-Net observations report
  55. GRB 210323A: Insight-HXMT/HE detection
  56. GRB 210321A: OSN Upper Limit
  57. GRB 210323A: MASTER optical observation
  58. GRB 210323A: Swift-BAT refined analysis
  59. GRB 210323A: Gemini-North Optical Source Detection
  60. Short GRB 210323A: GTC Observations
  61. GRB 210323B: Swift ToO observations
  62. Konus-Wind detection of GRB 210323A (short)
  63. GRB 210323A: Swift/UVOT Upper Limits
  64. GRB 210323A: Kitab optical upper limit
  65. GRB 210323A: Fermi GBM detection
  66. GRB 210323A: Mondy optical observations, counterpart detection
  67. GRB 210318A: Swift/UVOT Upper Limits
  68. GRB 210323A: Swift-XRT refined Analysis
  69. GRB 210323A: Enhanced Swift-XRT position
  70. GRB 210323A: NOT optical afterglow candidate
  71. Swift GRB 210323A: Global MASTER-Net observations report
  72. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  73. GRB 210323A: Nanshan/NEXT optical upper limit
  74. GRB 210323A: Swift detection of a short burst
  75. GRB 210321A: Swift/UVOT Detection
  76. Konus-Wind detection of GRB 210321A
  77. GRB 210318B: Swift/UVOT Upper Limits
  78. GRB 210321A: Swift-BAT refined analysis
  79. IceCube 135113_19489408.amon: Swift-XRT observations
  80. GRB 210321A: Swift-XRT refined Analysis
  81. GRB 210321A: NOT optical afterglow detection and redshift limit
  82. GRB 210321A: MASTER optical observation
  83. GRB 210321A: Enhanced Swift-XRT position
  84. GRB 210321A: DDOTI Afterglow Confirmation
  85. GRB 210321A: Swift/UVOT Detection
  86. GRB 210321A: Swift-XRT observations
  87. GRB 210321A: Swift detection of a burst
  88. GRB 210318B: MITSuME Okayama optical upper limits
  89. GRB 201216C: VIRT optical observations
  90. GRB 210318A: Swift-BAT refined analysis
  91. GRB 210318A: Swift-XRT refined Analysis
  92. GRB 210318A: Enhanced Swift-XRT position
  93. Swift GRB210318.13: Global MASTER-Net observations report
  94. GRB 210318B: Fermi GBM detection
  95. GRB 210318B: Swift-BAT refined analysis
  96. Swift GRB 210318A: Global MASTER-Net observations report
  97. Konus-Wind detection of GRB 210318B
  98. GRB210318B: Swift detection of a burst
  99. GRB 210318A: Swift detection of a burst
  100. GRB 210306A: GIT optical follow-up

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