What is a planetary nebula?
Planetary nebulae are clouds of dust and gas ejected from older stars as they move on to the next stage in their evolution. When a star uses up all its hydrogen fuel, and begins to burn helium, the core heats dramatically, causing the outer layers of the star to inflate dramatically. The outer layers of the star escape its gravity, and the solar wind of high energy particles and radiation accelerates the still superheated plasma out into space where it … Continue reading →