Planet formation and dynamics

Abstract:

Abstract The Origins Space Telescope (Origins) is one of four science and technology definition studies selected by the National Aeronautics and Space Administration (NASA) in preparation of the 2020 Astronomy and Astrophysics Decadal survey in the US. Origins will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. It is designed to answer three major science questions: How do galaxies form stars, make metals, and grow their central supermassive black holes from reionization? How do the conditions for habitability develop during the process of planet formation? Do planets orbiting M-dwarf stars support life? Origins operates at mid- to far-infrared wavelengths from ~ 2.8 μm to 588 μm, and is more than 1000 times more sensitive than prior far-IR missions due to its cold (~ 4.5 K) aperture and state-of-the-art instruments.

Abstract:

The tidal evolution of interacting binaries when the orbital period is short compared to the primary star's convective time scale is a problem of long-standing. Terquem (2021) has argued that, when this temporal ordering scheme is obeyed, the rate of energy transfer from tides to convection (denoted $D_R$) is given by the product of the averaged Reynolds stress associated with the tidal velocity and the mean shear associated with the convective flow. In a recent response, Barker and Astoul (2021, hereafter BA21) claim to show that $D_R$ (in this form) cannot contribute to tidal dissipation. Their analysis is based on a study of Boussinesq and anelastic models. Here, we demonstrate that BA21 misidentify the correct term responsible for energy transfer between tides and convection. As a consequence, their anelastic calculations do not prove that the $D_R$ formulation is invalidated as an energy-loss coupling between tides and convection. BA21 also carry out a calculation in the Boussinesq approximation. Here, their claim that $D_R$ once again does not contribute is based on boundary conditions that do not apply to any star or planet that radiates energy from its surface, which is a key dissipational process in the problem we consider.