https://www.space.com/possible-planet-habitable-zone-white-dwarf
Planetary debris, including some objects the size of moons, may hint at a rocky exoplanet within the habitable zone of a dead star, a new study suggests.
earthlike planetdead starmayorbiting
https://www.popsci.com/technology/article/2012-10/hyperspeed-scorching-super-earth-has-mantle-made-diamond/
New research says the planet has no water and is made primarily of carbon. It also shows that planets can be more complex to study than stars.
earthlike planetmade ofnearbydiamond