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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"

6667 results found.

  1. Swift follow-up of an Integral weak transient
  2. GRB 140211A: Swift-XRT and UVOT observations
  3. GRB 140215A: Swift-XRT refined Analysis
  4. GRB 140213A: Swift/UVOT Observations
  5. GRB 140213A: Fermi GBM Detection
  6. GRB 140213A: Swift-XRT refined Analysis
  7. GRB140209A: Swift/UVOT observations.
  8. GRB 140209A: Swift-XRT observations
  9. GRB 140209A: Fermi GBM observation
  10. GRB 140206A: Optical Observations via Virtual Telescope
  11. GRB 140206A: Swift-XRT refined Analysis
  12. GRB 140206A: T100 observations
  13. GRB 140206A: Fermi GBM detection
  14. GRB 140206B: Fermi-LAT detection
  15. GRB 140206B: Fermi GBM detection
  16. GRB 140129B: Swift-XRT refined Analysis
  17. GRB 140129A: Swift-XRT refined Analysis
  18. GRB 140110A: Second Follow-up Swift-XRT Observation
  19. Konus-Wind observation of GRB 131215A
  20. GRB 140118A: Fermi GBM observation
  21. GRB 140110A: Further Swift-XRT Observation
  22. GRB 140114A: Swift-XRT refined Analysis
  23. GRB 140104B: Further Swift XRT observations
  24. GRB 140114A: Swift detection of a burst
  25. GRB 140110A: Swift/UVOT Observations
  26. GRB 140110A: Swift XRT observations
  27. GRB 140110A: Fermi GBM observation
  28. GRB 140110A: Fermi-LAT detection of a burst
  29. GRB 140108A: Fermi GBM detection
  30. GRB 140108A: Swift-XRT refined Analysis
  31. Swift-BAT triggered on KS 1947+300
  32. GRB 140103A: Swift XRT afterglow confirmation
  33. GRB 140105A: Fermi GBM detection
  34. GRB 140104B: Fermi GBM observation
  35. GRB 140104B: Fermi-LAT detection of a burst
  36. GRB 131231A, Optical Observations
  37. GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
  38. GRB 140102A: Fermi/GBM Observation
  39. GRB 140103A: Swift-XRT refined analysis
  40. GRB 140102A: Swift-XRT refined Analysis
  41. GRB 140102A: Fermi-LAT detection of a burst
  42. GRB 131229A: Fermi GBM detection
  43. GRB 131231A: Swift-XRT observations
  44. GRB 131231A : xinglong TNT optical observation
  45. GRB 131231A: Fermi GBM detection
  46. GRB 131231A: Fermi-LAT detection of a burst
  47. GRB 131229A: Swift-XRT refined Analysis
  48. GRB 131227A: Swift-XRT refined Analysis
  49. GRB 131224A: Swift-XRT observation
  50. GRB 131216A: Fermi GBM observation
  51. GRB 131216A: Fermi-LAT detection of a burst
  52. GRB 131209A: Swift XRT and UVOT observations
  53. GRB 131209A: Fermi GBM observation
  54. GRB 131209A: Fermi-LAT detection of a burst
  55. GRB 131205A: Swift-XRT refined Analysis
  56. GRB 131127B: rejection of optical counterpart candidates
  57. GRB 131126A: Fermi GBM observation
  58. GRB 131202A: Swift-XRT refined Analysis
  59. GRB 131202A: Fermi GBM Detection
  60. GRB 131122A: Swift-XRT Further Observation
  61. GRB 131128A; Fermi GBM observation
  62. GRB 131128A: Swift-XRT refined Analysis
  63. GRB 131128A: T100 observations
  64. GRB 131127B: Fermi GBM detection
  65. GRB 131127A: Swift-XRT refined Analysis
  66. GRB 131122A: Swift-XRT observations
  67. GRB 131118A: Fermi GBM detection
  68. GRB 131117A: Swift-XRT refined Analysis
  69. GRB 131110A: Swift-XRT and UVOT upper limits
  70. GRB 131108A: Fermi GBM observation
  71. GRB 131108A: Swift-XRT observations
  72. GRB 131108A: Fermi-LAT refined analysis
  73. GRB 131108A: Swift detection of a possible X-ray afterglow
  74. GRB 131108A: Fermi-LAT onboard detection of a burst
  75. GRB 131031A: Swift-XRT afterglow confirmation
  76. GRB 131105A: Swift-XRT refined Analysis
  77. GRB 131105A: Fermi GBM observation
  78. GRB 131103A: Swift-XRT refined Analysis
  79. GRB 131031A: Fermi GBM detection
  80. GRB 131018B: Further Swift-XRT observations.
  81. GRB131030A : xinglong TNT optical observation
  82. GRB 131031A: Swift-XRT observations
  83. GRB 131030A: Swift-XRT refined Analysis
  84. GRB 131029A: Fermi GBM observation
  85. GRB 131029A: Fermi-LAT detection of a burst
  86. GRB 131028A: Fermi GBM detection
  87. Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
  88. GRB 131024B: Fermi GBM observation
  89. GRB 131024B : Xinglong TNT upper limit
  90. GRB 131024B: Swift-XRT refined Analysis
  91. GRB 131024A: Swift-XRT refined Analysis
  92. GRB 131018B: Swift/UVOT Upper Limits
  93. GRB 131018B: Swift-XRT observations
  94. GRB 131018B: Fermi GBM observation
  95. GRB 131018B: Fermi-LAT detection of a burst
  96. GRB 131018A: Swift-XRT refined Analysis
  97. GRB 131014A: Swift-XRT refined Analysis
  98. GRB 131011A: Swift/UVOT Upper Limits
  99. GRB 131014A: Swift/UVOT Upper Limits
  100. GRB 131014A: Enhanced XRT position

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