periapsis

This term serves as a general astronomical descriptor for the closest point of an orbit. It is the overarching category for more specific terms like perigee (Earth), perihelion (Sun), and periaspiron (star), allowing scientists to discuss orbital mechanics regardless of the specific central body involved.

In technical discourse, it is frequently contrasted with apoapsis, which denotes the furthest point in an orbit. The distance between these two points defines the eccentricity of the orbital ellipse.