A Preponderance of Perpendicular Planets

  title={A Preponderance of Perpendicular Planets},
  author={Simon H. Albrecht and Marcus L. Marcussen and Joshua N. Winn and Rebekah I. Dawson and Emil Knudstrup},
  journal={The Astrophysical Journal Letters},
Observing the Rossiter–McLaughlin effect during a planetary transit allows the determination of the angle λ between the sky projections of the star’s spin axis and the planet’s orbital axis. Such observations have revealed a large population of well-aligned systems and a smaller population of misaligned systems, with values of λ ranging up to 180°. For a subset of 57 systems, we can now go beyond the sky projection and determine the 3D obliquity ψ by combining the Rossiter–McLaughlin data with… 

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