Planetary nebulae are among the most beautiful objects in the universe. But why are they called that? What do they represent, and how do they form? We will answer these questions in this article.
How do planetary nebulae form?
Towards the end of their life cycle, red giants and supergiants with masses between 0.8 to 8 times that of the Sun shed their outer layers of material, leaving behind only their hot core, which is known as a white dwarf.
The material expelled by the star disperses into space and gradually dissipates. As the density of the nebula decreases, the radiation from the white dwarf ionizes the expanding gas, causing it to glow.
It is precisely these glowing clouds of gas with a white dwarf at their center, formed at the end of a star’s life cycle, that are called planetary nebulae.
Why are they named so?
French astronomer Charles Messier discovered The first planetary nebulae in the 18th century.
The first one he found (M27 or NGC 6854, also known as the Dumbbell Nebula) bore a striking resemblance to the planet Uranus in…
