An Etymological Dictionary of Astronomy and Astrophysics

Apparent proper motion exceeding the velocity of light seen toward certain astronomical objects, such as the jets of radio galaxies and quasars. However, these jets are not actually moving at speeds in excess of the speed of light: the apparent superluminal motion is a projection effect caused by objects moving near the speed of light and at a small angle to the line of sight.

Etymology (EN): → super-; luminal, from → lumen; → motion.

Etymology (PE): Jonbeš, → motion; abar→ super-; nur, → light.