Planetary Nebulae -

Planetary nebulae are glowing shells of gas and dust that are formed when a low-mass star reaches the end of its life and runs out of fuel to sustain nuclear fusion in its core. As the star's core contracts and heats up, the outer layers of the star expand and are ejected into space, forming a glowing shell of gas and dust around the dying star.

Despite their name, planetary nebulae have nothing to do with planets. They were named by early astronomers who observed them through telescopes and thought they looked like the disks of distant planets. In reality, planetary nebulae are relatively short-lived phenomena that occur during the final stages of a star's life.

Planetary nebulae can take on a variety of shapes, from simple round or elliptical shells to more complex and intricate structures. The shapes of planetary nebulae are thought to be influenced by the rotation of the star and the presence of any companion stars, as well as the distribution of gas and dust within the star's outer layers.

Planetary nebulae are important objects for astronomers to study, as they provide insights into the late stages of stellar evolution and the chemical enrichment of the interstellar medium. They are also visually stunning objects that can be easily observed with telescopes, making them a popular target for amateur astronomers.