Revision 1

Accepted · first revision · record

Title: What is the tidal dissipation factor of Sun-like stars?
Plain: 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: 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.
Settled by: Transit-timing measurements of orbital decay in many hot Jupiter systems over decades, combined with asteroseismic stellar structure.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: open
Status note: Orbital decay of WASP-12 b was established by 2020; whether its rapid decay reflects an evolved host star remains open.
Posed since: (empty)