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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 210402A: NOT optical afterglow candidate
  2. GRB 210402A: BOOTES-network early optical upper limit
  3. GRB 210403A: Swift-BAT refined analysis
  4. GRB 210402A: LBT observations
  5. GRB 210402A: DDOTI Upper Limits
  6. Swift GRB210403.35: Global MASTER-Net observations report
  7. GRB 210402A: Swift-XRT refined Analysis
  8. GRB 210403A: Swift detection of a burst
  9. GRB 210402A: Montarrenti Observatory upper limit
  10. GRB 210402A: Swift detection of a burst
  11. Swift GRB210402.92: Global MASTER-Net observations report
  12. GRB 210323A: Insight-HXMT/HE detection
  13. GRB 210321A: OSN Upper Limit
  14. GRB 210323A: MASTER optical observation
  15. GRB 210323A: Swift-BAT refined analysis
  16. GRB 210323A: Gemini-North Optical Source Detection
  17. Short GRB 210323A: GTC Observations
  18. GRB 210323B: Swift ToO observations
  19. Konus-Wind detection of GRB 210323A (short)
  20. GRB 210323A: Swift/UVOT Upper Limits
  21. GRB 210323A: Kitab optical upper limit
  22. GRB 210323A: Fermi GBM detection
  23. GRB 210318A: Swift/UVOT Upper Limits
  24. GRB 210323A: Swift-XRT refined Analysis
  25. GRB 210323A: Enhanced Swift-XRT position
  26. Swift GRB 210323A: Global MASTER-Net observations report
  27. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  28. GRB 210323A: Swift detection of a short burst
  29. GRB 210321A: Swift/UVOT Detection
  30. Konus-Wind detection of GRB 210321A
  31. GRB 210318B: Swift/UVOT Upper Limits
  32. GRB 210321A: Swift-BAT refined analysis
  33. IceCube 135113_19489408.amon: Swift-XRT observations
  34. GRB 210321A: Swift-XRT refined Analysis
  35. GRB 210321A: NOT optical afterglow detection and redshift limit
  36. GRB 210321A: MASTER optical observation
  37. GRB 210321A: Enhanced Swift-XRT position
  38. GRB 210321A: DDOTI Afterglow Confirmation
  39. GRB 210321A: Swift/UVOT Detection
  40. GRB 210321A: Swift-XRT observations
  41. GRB 210321A: Swift detection of a burst
  42. GRB 210318B: MITSuME Okayama optical upper limits
  43. GRB 210318A: Swift-BAT refined analysis
  44. GRB 210318A: Swift-XRT refined Analysis
  45. GRB 210318A: Enhanced Swift-XRT position
  46. Swift GRB210318.13: Global MASTER-Net observations report
  47. GRB 210318B: Fermi GBM detection
  48. GRB 210318B: Swift-BAT refined analysis
  49. Swift GRB 210318A: Global MASTER-Net observations report
  50. Konus-Wind detection of GRB 210318B
  51. GRB210318B: Swift detection of a burst
  52. GRB 210318A: Swift detection of a burst
  53. GRB 210306A: GIT optical follow-up
  54. GRB 210226A: GIT optical upper limit
  55. GRB 210306A: HCT optical upper limit
  56. Konus-Wind detection of GRB 210308A
  57. Konus-Wind detection of GRB 210306A
  58. Konus-Wind detection of GRB 210305A
  59. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  60. GRB 210306B: Fermi GBM detection
  61. GRB 210306A: Swift/UVOT Detection
  62. GRB 210308A: Swift-BAT refined analysis
  63. GRB 210307A: Swift-BAT refined analysis
  64. GRB 210308A: Swift/UVOT Detection
  65. GRB 210307A: Swift/UVOT Upper Limits
  66. GRB 210305A: Fermi GBM observation
  67. Swift GRB 210308A: Global MASTER-Net observations report
  68. GRB 210308A: Fermi GBM detection
  69. GRB 210305A: Swift-XRT refined Analysis
  70. GRB 210307A: Swift-XRT refined Analysis
  71. GRB 210306A: Swift-XRT refined Analysis
  72. GRB 210308A: MITSuME Okayama optical upper limits
  73. GRB 210308A: Swift detection of a burst with an optical counterpart
  74. GRB 210306A: Swift-BAT refined analysis
  75. GRB 210305A: Swift/UVOT Upper Limits
  76. GRB 210307A: LCO Optical Upper Limits
  77. GRB 210306B: Swift-BAT refined analysis
  78. GRB 210305A: Swift-BAT refined analysis
  79. GRB 210307A: Swift detection of a burst
  80. Swift GRB210307.36: Global MASTER-Net observations report
  81. GRB 210306A: MITSuME Akeno optical observation
  82. Swift GRB 210306A: Global MASTER-Net observations report
  83. GRB 210306A: Fermi GBM observation
  84. GRB 210306A: Fermi-LAT detection
  85. GRB 210306B: Swift detection of a burst
  86. GRB 210306A: LCO Optical Afterglow Detection
  87. GRB 210306A: DDOTI Afterglow Confirmation
  88. GRB 210306A: Swift detection of a burst with a bright optical counterpart
  89. Swift GRB 210305A: Global MASTER-Net observations report
  90. GRB 210305A: Swift detection of a burst
  91. Trigger 1035744: Swift detection of Sco X-1 due to Star Tracker loss of lock
  92. GRB 210226A: Swift/UVOT Upper Limits
  93. GRB 210226A: Swift-BAT refined analysis
  94. GRB 210226A: Fermi GBM detection
  95. GRB 210226A: KAIT Optical Upper Limit
  96. GRB 210226A: Swift-XRT refined Analysis
  97. Swift GRB 210226A: Global MASTER-Net observations report
  98. GRB 210218A: Swift-XRT confirmation of afterglow
  99. GRB 210226A: Enhanced Swift-XRT position
  100. GRB 210222B: 1.3m DFOT Optical upper limit

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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