Quasar. Illustration depicting a quasar (quasi- stellar object). Quasars are galaxies which are very distant but very luminous, so they appear star-like from Earth. The source of light appears concentrated in the nucleus, and is probably related to a central supermassive black hole. Such a system would probably have galactic jets emanating from the core along the rotational axis of the galaxy, as shown here. Quasars have high red shifts, so must be very distant and thus seen at a very early stage in the Universe's history. If light from a quasar passes through a closer galaxy, a gravitational arc or cross is often seen.