radial motion
noun Astronomy.
the component of the motion of a star away from or toward the earth along its line of sight, expressed in miles or kilometers per second and determined by the shift in the wavelength of light emitted by the star.
Also called
radial velocity.
Compare
redshift,
tangential motion.
Words nearby radial motion
British Dictionary definitions for radial velocity
radial velocity
noun
the component of the velocity of an object, esp a celestial body, directed along a line from the observer to the object