This gives the white dwarf a temporary thermonuclear lease on life. The Sun will end its life as a white dwarf about five billion years from now. Astronomer Gregory Shields reported recently his view that clouds of gases fly out of quasars at enormous speeds and result in nova explosions in the millions of stars surrounding the quasars. He further speculates that continual nova explosions in white dwarf stars could be the reason that these quasars seem to contain huge amounts of several heavy elements. Novae are the only known celestial objects that contain the percentages of heavy elements seen in certain quasars.
Quasars seem to be always associated with galaxies.