The dynamical process where a body in a multi-body system gains enough energy to escape the cluster's gravitational pull.Ejection is the dynamical process in which a body in a multi-body system gains enough kinetic energy to escape the gravitational pull of the entire system. This is a fundamental process in stellar dynamics, planetary formation, and even atomic physics. In a cluster of stars, for example, close encounters can transfer energy to a lighter star, giving it a velocity exceeding the escape velocity, thus ejecting it from the cluster.
The concept has been understood since the early studies of celestial mechanics, but its importance in stellar dynamics was highlighted by the work of Subrahmanyan Chandrasekhar and others in the mid-20th century, particularly in the context of star cluster evolution.
In a multi-body system, gravitational interactions between bodies can exchange energy. Through a series of close encounters, a particular body may receive a net positive energy relative to the system's potential well. When its total energy (kinetic plus potential) becomes positive, it is no longer bound and will fly away. This is often described as a 'slingshot' effect, where a heavier body transfers energy to a lighter one.
Ejection is used to explain the loss of stars from globular clusters, the formation of hypervelocity stars ejected from the galactic center, and in planetary science, the ejection of planetesimals from the solar system. It also plays a role in the design of spacecraft trajectories using gravity assists.
The article 'Квантовый побег с орбиты' suggests that quantum effects can influence ejection processes, where particles may tunnel out of a potential well, a purely quantum mechanical analog of classical ejection.
