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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

"200205A/SWIFT J0840.7-3516" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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"

19607 results found.

  1. GRB 210308A: Swift-BAT refined analysis
  2. GRB 210307A: Swift-BAT refined analysis
  3. GRB 210308A: Swift/UVOT Detection
  4. GRB 210307A: Swift/UVOT Upper Limits
  5. GRB 210305A: Fermi GBM observation
  6. Swift GRB 210308A: Global MASTER-Net observations report
  7. GRB 210308A: Fermi GBM detection
  8. GRB 210305A: Swift-XRT refined Analysis
  9. GRB 210307A: Swift-XRT refined Analysis
  10. GRB 210306A: Swift-XRT refined Analysis
  11. GRB 210308A: MITSuME Okayama optical upper limits
  12. GRB 210308A: Swift detection of a burst with an optical counterpart
  13. GRB 210306A: Swift-BAT refined analysis
  14. GRB 210305A: Swift/UVOT Upper Limits
  15. GRB 210307A: LCO Optical Upper Limits
  16. GRB 210306B: Swift-BAT refined analysis
  17. GRB 210305A: Swift-BAT refined analysis
  18. GRB 210307A: Swift detection of a burst
  19. Swift GRB210307.36: Global MASTER-Net observations report
  20. GRB 210306A: MITSuME Akeno optical observation
  21. Swift GRB 210306A: Global MASTER-Net observations report
  22. GRB 210306A: Fermi GBM observation
  23. GRB 210306A: Fermi-LAT detection
  24. GRB 210306B: Swift detection of a burst
  25. GRB 210306A: LCO Optical Afterglow Detection
  26. GRB 210306A: DDOTI Afterglow Confirmation
  27. GRB 210306A: Swift detection of a burst with a bright optical counterpart
  28. Swift GRB 210305A: Global MASTER-Net observations report
  29. GRB 210305A: Swift detection of a burst
  30. Trigger 1035744: Swift detection of Sco X-1 due to Star Tracker loss of lock
  31. GRB 210226A: Swift/UVOT Upper Limits
  32. GRB 210226A: Swift-BAT refined analysis
  33. GRB 210226A: Fermi GBM detection
  34. GRB 210226A: KAIT Optical Upper Limit
  35. GRB 210226A: Swift-XRT refined Analysis
  36. Swift GRB 210226A: Global MASTER-Net observations report
  37. GRB 210218A: Swift-XRT confirmation of afterglow
  38. GRB 210226A: Enhanced Swift-XRT position
  39. GRB 210222B: 1.3m DFOT Optical upper limit
  40. GRB 210226A: Swift detection of a burst
  41. GRB 210222B: MITSuME Akeno optical upper limits
  42. GRB 210222B: Swift-BAT refined analysis
  43. GRB 210222B: Swift-XRT refined Analysis
  44. GRB 210222B: Swift/UVOT Detection
  45. GRB 210222B: KAIT Optical Upper Limit
  46. GRB 210218A: Swift/UVOT observations
  47. GRB 210217A: Swift/UVOT Detection
  48. GRB 210222B: MASTER OT observation
  49. GRB 210222B: GOTO confirmation of afterglow detection
  50. GRB210222B: LCO Optical Afterglow Detection
  51. GRB210222B: BOOTES-1 optical afterglow detection
  52. GRB 210222B: Swift detection of a burst with an optical counterpart
  53. Swift GRB210222.94: Global MASTER-Net observations report
  54. GRB 210218A: Swift-XRT observations
  55. GRB 210212A: Lowell Discovery Telescope observations
  56. GRB 210217A: 1.3m DFOT optical detection
  57. GRB 210217A: Swift-XRT refined Analysis
  58. GRB 210218A: Swift-BAT refined analysis
  59. Fermi GBM Sub-Threshold Detection of GRB 210217A
  60. GRB 210217A: Liverpool Telescope First Hour Observations
  61. GRB 210217A: Swift-BAT refined analysis
  62. GRB 210217A: KAIT Optical Observations
  63. GRB 210218A: MITSuME Akeno optical upper limits
  64. GRB 210218A： GWAC-F60A optical upper limit
  65. GRB 210218A: NEXT optical upper limit
  66. GRB 210218A: Swift detection of a burst
  67. GRB 210205A: observations with the 3.6m DOT, a potential dark burst?
  68. GRB 210217A: Enhanced Swift-XRT position
  69. Fermi/GBM observation of a burst from SGR 1830-0645
  70. GRB 210217A: NEXT early optical afterglow observations
  71. GRB 210217A: Swift detection of a burst with an optical counterpart
  72. GRB 210210A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  73. Swift Trigger 1033144: Detection of SGR 1830-0645
  74. GRB 210212B: Swift ToO observations
  75. IPN triangulation of GRB 210212B (consistent with ZTF21aakruew/AT2021cwd)
  76. GRB 210212A: 1.3m DFOT Optical upper limit
  77. GRB 210212A: Gemini South optical observations
  78. Swift Trigger 1032350: Detection of SGR 1830-0645
  79. GRB 210212A: Possible host galaxy counterpart with the NOT
  80. Swift GRB 210212A: Global MASTER-Net observations report
  81. GRB 210212A: MITSuME Akeno optical upper limits
  82. GRB 210212A: Swift-XRT refined Analysis
  83. GRB 210212A: BOOTES-4/MET optical upper limit
  84. GRB 210212A: Swift/UVOT Upper Limits
  85. GRB 210212A: Swift-BAT refined analysis
  86. GRB 210212A: Enhanced Swift-XRT position
  87. GRB 210212A: Swift detection of a burst
  88. GRB 210207B: GECAM detection
  89. GRB 210211A: Swift/UVOT Detection
  90. GRB 210211A: Swift-XRT refined Analysis
  91. GRB 210211A: Swift-BAT refined analysis
  92. GRB 210211A: Fermi GBM observation
  93. Swift-XRT observations of IceCube-210210A
  94. GRB 210209A: Swift-BAT refined analysis
  95. GRB 210211A: Enhanced Swift-XRT position
  96. GRB 210211A: MASTER optical observation of REM OT
  97. GRB 210211A: Swift detection of a burst
  98. Swift GRB210211.36: Global MASTER-Net observations report
  99. GRB 210210A: Swift-BAT refined analysis
  100. GRB 210209A: BOOTES-4/MET optical upper limit

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