 Proper motion

Proper motion is the apparent angular motion of a star or other celestial object across the sky, as observed from a specific location over time. It is measured in arcseconds per year and represents the object's movement perpendicular to the line of sight from the observer. Proper motion is a consequence of the object's actual motion through space relative to the observer, combined with the effects of the observer's position (like being on Earth) and the object's distance.

Some stars are so close that we can actually see their angles move with time due to the relative motion between them and the Sun, e.g. Proxima Centauri!