Tidal Evolution in Binaries Containing Solar-Type Stars

Phil Arras

November 24, 2011

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Abstract: Star-star and star-planet binaries at close separation can undergo evolution due to tides. This “tidal friction” can synchronize and align the spins, as well as circularize the orbits, and cause orbits to decay. I’ll review observational evidence for such tidal evolution, and then discuss theories which try to account for the observed evolution rates. The main focus will be on recent work in which it is shown that linear tidal flow is unstable over a large range of parameter space, and short wavelength g-modes grow and saturate in a turbulent state, which may provide enhanced dissipation relative to the linear calculation.