Stellar oscillations induced by the passage of a fast stellar object

TL;DR

This paper explores how fast stellar objects passing near stars can induce observable oscillations through gravitational interactions, potentially causing detectable luminosity changes within hours.

Contribution

It introduces a model for gravitationally induced stellar oscillations caused by fast stellar objects and identifies conditions for resonance and observability.

Findings

Resonant oscillations occur at specific velocities and distances.

Luminosity changes can be detected within hours.

Such near-miss events are more frequent than direct collisions.

Abstract

We investigate induced oscillations by the gravitational field of a fast stellar object, such as a neutron star or a black-hole in a near miss collision with another star. Non-adiabatic collision conditions may lead to large amplitude oscillations in the star. We show that for a solar-type star a resonant condition can be achieved by a fast moving stellar object with velocity in the range of 100 km/s to 1000 km/s, passing at a distance of a few multiples of the star radius. Although such collisions are rare, they are more frequent than head-on collisions, and their effects could be observed through a visible change of the star luminosity occurring within a few hours.