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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.

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"

3050 results found.

  1. GRB 140508A: Swift-XRT observations
  2. GRB 140506A: Swift-XRT refined Analysis
  3. GRB 140502A: Swift-XRT refined Analysis
  4. GRB 140430A: Swift-XRT refined Analysis
  5. GRB 140423A: Nishi-Harima NIR Observations
  6. GRB 140423A: Swift-XRT refined Analysis
  7. GRB 140419A: Continued RATIR Optical and NIR Observations
  8. Konus-Wind observation of GRB 140419A
  9. GRB 140419A: Swift-XRT refined Analysis
  10. GRB 140414A: Swift/UVOT Upper Limit
  11. GRB 140414A: Swift-XRT observations
  12. GRB 140413A: Swift-XRT refined Analysis
  13. GRB 140412A: Swift-XRT refined Analysis
  14. Swift Trigger 595345 is not an astrophysical source
  15. GRB 140408A: Swift-XRT refined Analysis
  16. GRB 140402A: Swift-XRT observations
  17. Swift trigger 594286: Is likely a noise trigger
  18. GRB 140331A: Swift-XRT refined Analysis
  19. Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A
  20. GRB 140323A: Swift-XRT refined Analysis
  21. GRB 140320C: Swift/UVOT Upper Limits
  22. GRB 140320C: Swift-XRT observations
  23. GRB 140320A: Confirmation of a fading X-ray afterglow
  24. GRB 140320C: Swift-XRT detection of the X-ray afterglow
  25. GRB 140320B: Swift-XRT detection of the afterglow
  26. GRB 140320A: Swift-XRT detection of an afterglow candidate
  27. Swift Trigger 592558 is not an astrophysical source
  28. GRB 140318A: Swift-XRT refined Analysis
  29. GRB 140311C: Swift-XRT and UVOT observations
  30. GRB 140311A: Swift-XRT refined Analysis
  31. GRB 140311B: Swift-XRT refined Analysis
  32. GRB 140304A: Swift-XRT refined Analysis
  33. GRB 140302A: Swift/UVOT Upper Limits
  34. GRB 140302A: Swift-XRT refined Analysis
  35. GRB 140301A: Swift-XRT refined Analysis
  36. iPTF14yb: Swift-XRT detection
  37. GRB 140219A: XRT afterglow candidate
  38. GRB 140221A: Results from Swift XRT tiled observations
  39. GRB 140219A: results from Swift XRT and UVOT tiled observations
  40. Swift follow-up of an Integral weak transient
  41. GRB 140211A: Swift-XRT and UVOT observations
  42. GRB 140215A: Swift-XRT refined Analysis
  43. GRB 140213A: Swift/UVOT Observations
  44. GRB 140213A: Swift-XRT refined Analysis
  45. GRB140209A: Swift/UVOT observations.
  46. GRB 140209A: Swift-XRT observations
  47. GRB 140206A: Swift-XRT refined Analysis
  48. GRB 140129B: Swift-XRT refined Analysis
  49. GRB 140129A: Swift-XRT refined Analysis
  50. GRB 140110A: Second Follow-up Swift-XRT Observation
  51. GRB 140110A: Further Swift-XRT Observation
  52. GRB 140114A: Swift-XRT refined Analysis
  53. GRB 140104B: Further Swift XRT observations
  54. GRB 140110A: Swift/UVOT Observations
  55. GRB 140110A: Swift XRT observations
  56. GRB 140108A: Swift-XRT refined Analysis
  57. Swift-BAT triggered on KS 1947+300
  58. GRB 140103A: Swift XRT afterglow confirmation
  59. GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
  60. GRB 140103A: Swift-XRT refined analysis
  61. GRB 140102A: Swift-XRT refined Analysis
  62. GRB 131231A: Swift-XRT observations
  63. GRB 131229A: Swift-XRT refined Analysis
  64. GRB 131227A: Swift-XRT refined Analysis
  65. GRB 131224A: Swift-XRT observation
  66. GRB 131209A: Swift XRT and UVOT observations
  67. GRB 131205A: Swift-XRT refined Analysis
  68. GRB 131127B: rejection of optical counterpart candidates
  69. GRB 131202A: Swift-XRT refined Analysis
  70. GRB 131122A: Swift-XRT Further Observation
  71. GRB 131128A: Swift-XRT refined Analysis
  72. GRB 131127A: Swift-XRT refined Analysis
  73. GRB 131122A: Swift-XRT observations
  74. GRB 131117A: Swift-XRT refined Analysis
  75. GRB 131110A: Swift-XRT and UVOT upper limits
  76. GRB 131108A: Swift-XRT observations
  77. GRB 131108A: Fermi-LAT refined analysis
  78. GRB 131108A: Swift detection of a possible X-ray afterglow
  79. GRB 131031A: Swift-XRT afterglow confirmation
  80. GRB 131105A: Swift-XRT refined Analysis
  81. GRB 131103A: Swift-XRT refined Analysis
  82. GRB 131018B: Further Swift-XRT observations.
  83. GRB 131031A: Swift-XRT observations
  84. GRB 131030A: Swift-XRT refined Analysis
  85. Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
  86. GRB 131024B: Swift-XRT refined Analysis
  87. GRB 131024A: Swift-XRT refined Analysis
  88. GRB 131018B: Swift/UVOT Upper Limits
  89. GRB 131018B: Swift-XRT observations
  90. GRB 131018A: Swift-XRT refined Analysis
  91. GRB 131014A: Swift-XRT refined Analysis
  92. GRB 131011A: Swift/UVOT Upper Limits
  93. GRB 131014A: Swift/UVOT Upper Limits
  94. GRB 131014A: Enhanced XRT position
  95. Swift-XRT detection of iPTF 13dsw/Fermi403206457
  96. GRB 131004A: MOSFIRE NIR imaging
  97. GRB 131004A: Swift-XRT refined Analysis
  98. GRB 131002B: Swift-XRT Refined Analysis
  99. GRB 131002A: Swift-XRT refined Analysis
  100. GRB 130925A: continuing Swift/XRT monitoring

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