White Dwarfs

After medium-sized stars like our Sun die and explode into a spectacular planetary nebula, what remains of its core will become a white dwarf. After our sun dies and becomes a white dwarf, it will only be about the size of our earth, but with a surface gravity over 100,000 times higher than Earth's. Eventually, these white dwarf stars will cool into black dwarfs, but this process is theorized to take 100 billion billion years. That’s so far into the future that no regular stars will shine anymore, galaxies will have evaporated, and only then will the first white dwarf turn into the first black dwarf. Planets around white dwarfs could be humanity's last home right before the death of the universe.