Stellar Pulsations excited by a scattered mass

TL;DR

This paper analyzes gravitational wave signals from a mass scattering off a star, highlighting the excitation of stellar quasi-normal modes and their dependence on proximity, differing from black hole interactions.

Contribution

It introduces a computation of gravitational wave energy spectra showing stellar quasi-normal modes are excited during scattering, unlike black holes.

Findings

Stellar quasi-normal modes are excited during scattering.

Energy emission depends on the closest approach to the star.

The process differs from black hole scattering in mode excitation.

Abstract

We compute the energy spectra of the gravitational signals emitted when a mass m is scattered by the gravitational field of a star of mass M >> m. We show that, unlike black holes in similar processes, the quasi-normal modes of the star are excited, and that the amount of energy emitted in these modes depends on how close the exciting mass can get to the star.