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Title: INTERNAL GRAVITY WAVES MODULATE THE APPARENT MISALIGNMENT OF EXOPLANETS AROUND HOT STARS

Journal Article · · Astrophysical Journal Letters
 [1];  [2];  [3]
  1. Department of Planetary Sciences, University of Arizona, Tucson, AZ 85719 (United States)
  2. Astronomy and Astrophysics Department, University of California, Santa Cruz, CA 95064 (United States)
  3. Argelander-Institut for Astronomie Universit Bonn Auf dem Huegel 71, D-53121 Bonn (Germany)

We propose that the observed misalignment between extrasolar planets and their hot host stars can be explained by angular momentum transport within the host star. Observations have shown that this misalignment is preferentially around hot stars, which have convective cores and extended radiative envelopes. This situation is amenable to substantial angular momentum transport by internal gravity waves (IGW) generated at the convective-radiative interface. Here, we present numerical simulations of this process and show that IGW can modulate the surface rotation of the star. With these two-dimensional simulations, we show that IGW could explain the retrograde orbits observed in systems such as HAT-P-6 and HAT-P-7. However, extension to high-obliquity objects will await future three-dimensional simulations. We note that these results also imply that individual massive stars should show temporal variations in their v sin i measurements.

OSTI ID:
22078516
Journal Information:
Astrophysical Journal Letters, Vol. 758, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English