What is the tidal dissipation factor of Sun-like stars?
In plain words
Tides raised by a close giant planet on its star slowly drag the planet inward. How strongly stars dissipate tidal energy decides how long hot Jupiters survive.
Precise statement
Determine the modified tidal quality factor $Q'_{*}$ of solar-type stars at tidal periods $\sim 1\,\mathrm{d}$ and its dependence on stellar structure. WASP-12 b shows orbital decay with $dP/dt$ of approximately $-29\,\mathrm{ms}/\mathrm{yr}$, giving $Q'_{*}$ of approximately $2x10^{5}$, while other systems imply $Q'_{*} > 10^{7}$. The answer is $Q'_{*}$ as a function of stellar mass, age and tidal frequency.
What would settle it
Transit-timing measurements of orbital decay in many hot Jupiter systems over decades, combined with asteroseismic stellar structure.
Status in the literature
Orbital decay of WASP-12 b was established by 2020; whether its rapid decay reflects an evolved host star remains open.