“A bit of mould is a pleiad of flowers; a nebula is an ant-hill of stars.” -Victor Hugo
Nothing lives forever, not even the stars. Our Sun, like all true stars, thrives on nuclear fusion in its core.
At millions of degrees, it converts hydrogen into helium, and will later heat up further, fusing helium into carbon.
Like most stars, it will never get hot enough to go supernova. When it runs out of fuel, it will contract into a white dwarf, blowing off its outer layers, forming a planetary nebula.
This example of cosmic recycling will send both hydrogen and heavier elements back into the interstellar medium.
Stars up to 800% the mass of the Sun will achieve this fate, with planetary nebulae taking on a variety of morphologies.
Single stars may blow off their outer layers spherically, like 20% of planetary nebulae.
Stars with binary companions may produce spirals or other asymmetrical shapes.
Most commonly, bipolar nebulae may originate from rapidly rotating stars.
The most spectacular images of this natural phenomenon come from Hubble, which assigns different colors to individual elements, temperatures or spectral features.
In another 7 billion years, our Sun will die in this manner, like only one-in-four stars in our Universe.