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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"

6403 results found.

  1. GRB 131127A: Swift-XRT refined Analysis
  2. GRB 131122A: Swift-XRT observations
  3. GRB 131118A: Fermi GBM detection
  4. GRB 131117A: Swift-XRT refined Analysis
  5. GRB 131110A: Swift-XRT and UVOT upper limits
  6. GRB 131108A: Fermi GBM observation
  7. GRB 131108A: Swift-XRT observations
  8. GRB 131108A: Fermi-LAT refined analysis
  9. GRB 131108A: Swift detection of a possible X-ray afterglow
  10. GRB 131108A: Fermi-LAT onboard detection of a burst
  11. GRB 131031A: Swift-XRT afterglow confirmation
  12. GRB 131105A: Swift-XRT refined Analysis
  13. GRB 131105A: Fermi GBM observation
  14. GRB 131103A: Swift-XRT refined Analysis
  15. GRB 131031A: Fermi GBM detection
  16. GRB 131018B: Further Swift-XRT observations.
  17. GRB131030A : xinglong TNT optical observation
  18. GRB 131031A: Swift-XRT observations
  19. GRB 131030A: Swift-XRT refined Analysis
  20. GRB 131029A: Fermi GBM observation
  21. GRB 131029A: Fermi-LAT detection of a burst
  22. GRB 131028A: Fermi GBM detection
  23. Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
  24. GRB 131024B: Fermi GBM observation
  25. GRB 131024B : Xinglong TNT upper limit
  26. GRB 131024B: Swift-XRT refined Analysis
  27. GRB 131024A: Swift-XRT refined Analysis
  28. GRB 131018B: Swift/UVOT Upper Limits
  29. GRB 131018B: Swift-XRT observations
  30. GRB 131018B: Fermi GBM observation
  31. GRB 131018B: Fermi-LAT detection of a burst
  32. GRB 131018A: Swift-XRT refined Analysis
  33. GRB 131014A: Swift-XRT refined Analysis
  34. GRB 131011A: Swift/UVOT Upper Limits
  35. GRB 131014A: Swift/UVOT Upper Limits
  36. GRB 131014A: Enhanced XRT position
  37. GRB 131014A: NOT afterglow candidate
  38. GRB 131014A: Fermi-LAT detection
  39. GRB 131014A: Fermi GBM detection
  40. GRB 131011A: Fermi GBM detection
  41. Swift-XRT detection of iPTF 13dsw/Fermi403206457
  42. Fermi403206457: NOT optical observations
  43. GRB 131004A: MOSFIRE NIR imaging
  44. GRB 131004A: Fermi GBM observation
  45. GRB 131004A: Swift-XRT refined Analysis
  46. GRB 131004A: Liverpool Telescope optical afterglow observations
  47. GRB 131002A: Fermi GBM observation
  48. GRB 131002B: Swift-XRT Refined Analysis
  49. GRB 131002A: Swift-XRT refined Analysis
  50. GRB 130925A: continuing Swift/XRT monitoring
  51. GRB 130929A: Swift-XRT refined Analysis
  52. Fermi LAT Upper Limits on GRB 130925A
  53. GRB 130925A: Swift/UVOT Detection of the Host Galaxy
  54. GRB 130925A: Fermi GBM Detection
  55. GRB 130925A: Historical non-detection from Rosat-HRI
  56. Fermi GBM detection of GRB 130925A and a possible precursor
  57. GRB 130925A: Swift-XRT refined Analysis
  58. GRB 130831A: RTT150 optical observations
  59. GRB 130702A: RTT150 optical observations
  60. GRB 130907A: Maidanak optical observations
  61. GRB 130903A: Further Swift XRT observations.
  62. GRB 130606A: Chandra observation
  63. GRB 130912A: Swift-XRT refined Analysis
  64. GRB 130912A: Fermi GBM detection
  65. GRB 120419A: Swift XRT confirmation of the afterglow
  66. GRB 130907A: T21 optical observations
  67. GRB 130907A: Swift-XRT refined Analysis
  68. GRB 120916A: Fermi-LAT detection of a burst
  69. Swift follow-up results of the possible weak INTEGRAL GRB
  70. GRB 130903A: Swift/UVOT Upper Limits
  71. Swift follow-up of an INTEGRAL possible weak GRB
  72. GRB 130903A: Fermi GBM observation
  73. GRB 130903A: Swift-XRT observations
  74. Swift trigger 569022 is a new Galactic source Swift J1734.5-3027
  75. GRB 130831A: Optical Observations via Virtual Telescope, follow-up
  76. GRB 130831A: T100 observations
  77. GRB 130831B: Swift-XRT refined Analysis
  78. GRB 130831A: Optical Observations via Virtual Telescope
  79. GRB 130831A: Swift-XRT refined Analysis
  80. GRB 130831A: MITSuME Akeno Optical observation
  81. GRB 130828A: Swift XRT and UVOT observations
  82. GRB 130828A: Fermi GBM detection
  83. GRB 130828A: Fermi-LAT detection of a burst
  84. GRB 130821A: Swift-XRT observation
  85. GRB 130822A: Swift-XRT refined Analysis
  86. GRB 130821A: Fermi-LAT detection of a burst
  87. GRB 130821A: Fermi GBM Detection
  88. GRB 130816A: Swift-XRT refined Analysis
  89. GRB 130816A: Fermi GBM observation
  90. GRB 130816B: Swift-XRT refined Analysis
  91. GRB 130812A: Swift-XRT refined Analysis
  92. GRB 130807A: Swift-XRT refined analysis
  93. GRB 130807A, Swift-BAT refined analysis
  94. GRB 130623A: GROND detection of the optical/NIR afterglow
  95. GRB 130806A: Swift-XRT refined Analysis
  96. GRB 130804A; Fermi GBM observation
  97. GRB 130803A: Swift-XRT refined Analysis
  98. GRB 130803A; Fermi GBM observation
  99. GRB 130727A: Swift-XRT refined Analysis
  100. GRB 130727A: Fermi GBM detection

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