Planetary nebulae are some of the most beautiful objects in the universe.
They arise when, at the end of their life cycle, stars with a mass of 0.8 to 8 solar masses shed their outer layers of matter, and a compact core remains in place of the star - a white dwarf.
It is these luminous clouds of gas with a white dwarf at the center that are called planetary nebulae.
Such objects live very little by astronomical standards, only 10-15 thousand years. #puzzle @puzzle 19:30
