Jul 12, 2013 9:51 AM by Stephen Bowers
Our sun is one of billions among billions of stars. Stars burn through various elements, and when stars burn up all of the hydrogen in their cores, they cool and expand in size. Radiation from the star and wind created by the intense heating at the star's core shape the gases and creates a complex-looking structure called a "planetary nebula."
The image at the top of this article is from NASA. It shows the Eskimo Nebula, also known as NGC 2392. The image is a composite and contains x-ray data. The purple center of the nebula is the star's core, which NASA says is about a million degrees in temperature. Around the edges, the outward moving gas from the star can be seen.
This nebula is the remnant of a star that will eventually collapse into a white dwarf star. Following the white dwarf star phase, it could explode and form into a nova or super nova.
Our own star, the sun, is expected to go through this process in about 5 billion years.