Accumulated Tidal Heating of Stars Over Multiple Pericenter Passages Near SgrA*

TL;DR

This paper demonstrates that repeated tidal interactions with the supermassive black hole at the Galactic center can cause stars to heat up and eventually disrupt at larger distances than previously thought, explaining the absence of close-in massive stars.

Contribution

It introduces a model of long-term tidal heating accumulation over multiple passages, revealing a potential mechanism for star disruption at greater distances from SgrA* than standard models predict.

Findings

Tidal excitation energy grows linearly with the number of passages.

Stars can be disrupted at 4-5 times the standard tidal radius.

This process explains the scarcity of massive stars close to 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*.