Surprising Impacts of Gravity Waves
James Fuller (Caltech)
October 21, 2019
Abstract: Gravity waves are low frequency fluid oscillations restored by buoyancy forces in planetary and stellar interiors. Despite their ubiquity, the importance of gravity waves in evolutionary processes and asteroseismology has only recently been appreciated. In stars and planets, orbital resonances with standing gravity waves in the stellar/planetary interior can accelerate tidal evolution, especially when such resonances are maintained by a resonance locking mechanism. This process can explain observations of tidally excited pulsations in heartbeat stars and the rapid observed migration of Saturn’s moons. In the late phase evolution of massive stars approaching core-collapse, vigorous convection excites gravity waves that can redistribute huge amounts of energy and angular momentum within the star. I will present preliminary models of this process, showing how wave energy redistribution can drive outbursts and enhanced mass loss in the final years of massive star evolution, with important consequences for the appearance of subsequent supernovae.