Accumulated tidal heating of stars over multiple pericentre passages near SgrA*

Abstract

We consider the long-term tidal heating of a star by the supermassive black hole at the Galactic center, SgrA*. We show that gravitational interaction with background stars leads to a linear growth of the tidal excitation energy with the number of pericenter passages near SgrA*. The accumulated heat deposited by excitation of modes within the star over many pericenter passages can lead to a runaway disruption of the star at a pericenter distance that is 4-5 times farther than the standard tidal disruption radius. The accumulated heating may explain the lack of massive ($\gtrsim 10M_{\odot}$) S-stars closer than several tens of AU from SgrA*.