transverse velocity

Ta star's velocity components

Image credit: CSIRO Australia.

Transverse velocity is the component of the velocity of an object, such as a star, that is at right-angles to the observer's line of sight; also known as tangential velocity. To calculate a star's transverse velocity, the star's distance and proper motion must be known. If the transverse velocity and radial velocity are known, it is a simple matter to calculate the object's velocity through space.