What is a planetary nebula?

The star turns into a red giant when the majority of its hydrogen is burned, pushing out gases due to the heat and pressure from burning helium. The star's outer layers are then puffed up to create a gas cloud surrounding the star, known as a planetary nebula.

When some star types shed their outer layers as they develop into white dwarfs, they release an expanding, glowing shell of ionized gas that forms a nebula that can take on complex shapes resembling planets. This type of nebula is known as a planetary nebula.

A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from certain types of stars late in their lives. These stars shed their outer layers of gas as they evolve into white dwarfs, and the expelled gas forms a nebula that is often roughly spherical in shape, resembling a planet when viewed through early telescopes. The central star, which is usually a white dwarf, illuminates the surrounding gas, causing it to emit light in various colors. Planetary nebulae are important objects in the study of stellar evolution and play a role in enriching interstellar space with heavy elements produced in the stars' cores.