The Helix Nebula (NGC 7293) is a large planetary nebula located in the constellation Aquarius about 700 light-years away and spans about 2.5 light-years. Gases from the star in the surrounding space appear, from our vantage point, as if we are looking down a helix structure. The remnant central stellar core, known as a planetary nebula nucleus or PNN, is destined to become a white dwarf star. The observed glow of the central star is so energetic that it causes the previously expelled gases to brightly fluoresce.