quasar -
An extragalactic object, starlike in appearance, that is among the most luminous and thought to be the most distant objects in the universe.
Wikipedia
A quasi-stellar radio source ("quasar") is a very energetic and distant galaxy with an active galactic nucleus. They are the most luminous objects in the universe. Quasars were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than extended sources similar to galaxies.
