Planetary remnants around white dwarf stars
When a star like our sun gets to be old, in another seven billion years or so, it will no longer be able to sustain burning its nuclear fuel. With only about half of its mass remaining it will shrink to a fraction of its radius and become a white dwarf star. White dwarf stars are common; over 95% of all stars will become white dwarfs. The most famous one is the companion to the brightest star in the sky, Sirius, but more particularly all stars known to host exoplanets will also end their lives as white dwarfs.
phys.org
Go to Source