White+Dwarf.

White Dwarf  A White dwarf is half the size of our sun, and that’s what makes it dense. They are like stars but they are past burning stage which means they have no more life because of all their fuel is burnet up from the sun's heat. After that the star expels most of its outer layer and is then formed into something called a planetary nebula, then all there is left of that star is the extremely hot core and then forms into a white dwarf, then the core cools down in the next billion years or so.