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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"

27971 results found.

  1. GRB 210318A: Enhanced Swift-XRT position
  2. Swift GRB210318.13: Global MASTER-Net observations report
  3. GRB 210318B: Fermi GBM detection
  4. GRB 210318B: Swift-BAT refined analysis
  5. Swift GRB 210318A: Global MASTER-Net observations report
  6. Konus-Wind detection of GRB 210318B
  7. GRB210318B: Swift detection of a burst
  8. GRB 210318A: Swift detection of a burst
  9. GRB 210317A: GECAM detection
  10. GRB 210317A: Fermi GBM Final Real-time Localization
  11. GRB 210306A: GIT optical follow-up
  12. GRB 210226A: GIT optical upper limit
  13. GRB 210306A: HCT optical upper limit
  14. GRB 210312A: Fermi GBM Final Real-time Localization
  15. Konus-Wind detection of GRB 210308A
  16. Konus-Wind detection of GRB 210306A
  17. Konus-Wind detection of GRB 210305A
  18. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  19. GRB 210306B: Fermi GBM detection
  20. GRB 210306A: Swift/UVOT Detection
  21. GRB 210308A: Swift-BAT refined analysis
  22. GRB 210307A: Swift-BAT refined analysis
  23. GRB 210308A: Swift/UVOT Detection
  24. GRB 210307A: Swift/UVOT Upper Limits
  25. GRB 210305A: Fermi GBM observation
  26. Swift GRB 210308A: Global MASTER-Net observations report
  27. GRB 210308A: Fermi GBM detection
  28. GRB 210305A: Swift-XRT refined Analysis
  29. GRB 210307A: Swift-XRT refined Analysis
  30. GRB 210306A: Swift-XRT refined Analysis
  31. GRB 210308A: MITSuME Okayama optical upper limits
  32. GRB 210308A: Swift detection of a burst with an optical counterpart
  33. GRB 210306A: Swift-BAT refined analysis
  34. GRB 210305A: Swift/UVOT Upper Limits
  35. GRB 210307B: GECAM detection
  36. GRB 210307A: LCO Optical Upper Limits
  37. GRB 210306B: Swift-BAT refined analysis
  38. GRB 210305A: Swift-BAT refined analysis
  39. GRB 210307A: Swift detection of a burst
  40. Swift GRB210307.36: Global MASTER-Net observations report
  41. GRB 210306A: MITSuME Akeno optical observation
  42. Swift GRB 210306A: Global MASTER-Net observations report
  43. GRB 210306A: Fermi GBM observation
  44. GRB 210306A: Fermi-LAT detection
  45. GRB 210306B: Swift detection of a burst
  46. GRB 210306A: LCO Optical Afterglow Detection
  47. GRB 210306A: DDOTI Afterglow Confirmation
  48. GRB 210306A: Swift detection of a burst with a bright optical counterpart
  49. Swift GRB 210305A: Global MASTER-Net observations report
  50. GRB 210305A: Swift detection of a burst
  51. GRB 210228B: Insight-HXMT/HE detection
  52. Trigger 1035744: Swift detection of Sco X-1 due to Star Tracker loss of lock
  53. GRB 210226A: Swift/UVOT Upper Limits
  54. GRB 210228A: GECAM detection
  55. Integral GRB210227.19: MASTER OT retraction
  56. GRB 210225A: Insight-HXMT/HE detection
  57. Integral GRB210227.19: Global MASTER-Net OT detection
  58. GRB 210226A: Swift-BAT refined analysis
  59. GRB 210226A: Fermi GBM detection
  60. GRB 210226A: KAIT Optical Upper Limit
  61. GRB 210226A: Swift-XRT refined Analysis
  62. Swift GRB 210226A: Global MASTER-Net observations report
  63. GRB 210218A: Swift-XRT confirmation of afterglow
  64. GRB 210226A: Enhanced Swift-XRT position
  65. GRB 210222B: 1.3m DFOT Optical upper limit
  66. GRB 210226A: Swift detection of a burst
  67. GRB 210222B: MITSuME Akeno optical upper limits
  68. Konus-Wind detection of GRB 210222A
  69. GRB 210222B: VIRT optical detection
  70. GRB 210222B: Swift-BAT refined analysis
  71. GRB 210222B: Swift-XRT refined Analysis
  72. GRB 210222B: Swift/UVOT Detection
  73. GRB 210222B: KAIT Optical Upper Limit
  74. GRB 210222B: FRAM-ORM afterglow detection
  75. GRB 210218A: Swift/UVOT observations
  76. GRB 210217A: Swift/UVOT Detection
  77. GRB 210222B: MASTER OT observation
  78. GRB 210222A: CALET Gamma-Ray Burst Monitor detection
  79. GRB 210222B: GOTO confirmation of afterglow detection (correction to GCN29548)
  80. GRB 210222B: Liverpool Telescope optical detection
  81. GRB 210222B: GOTO confirmation of afterglow detection
  82. GRB210222B: LCO Optical Afterglow Detection
  83. GRB210222B: BOOTES-1 optical afterglow detection
  84. GRB 210222B: Swift detection of a burst with an optical counterpart
  85. Swift GRB210222.94: Global MASTER-Net observations report
  86. GRB 210222A: MAXI/GSC detection
  87. GRB 210218A: Swift-XRT observations
  88. uGMRT radio detection of GRB 210204A
  89. GRB 210212A: Lowell Discovery Telescope observations
  90. GRB 210217A: 1.3m DFOT optical detection
  91. GRB 210217A: Swift-XRT refined Analysis
  92. GRB 210218A: Swift-BAT refined analysis
  93. Fermi GBM Sub-Threshold Detection of GRB 210217A
  94. GRB 210217A: Liverpool Telescope First Hour Observations
  95. GRB 210217A: Swift-BAT refined analysis
  96. GRB 210217A: KAIT Optical Observations
  97. GRB 210218A: MITSuME Akeno optical upper limits
  98. GRB 210218A： GWAC-F60A optical upper limit
  99. GRB 210218A: NEXT optical upper limit
  100. GRB 210218A: Swift detection of a burst

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