Humans tend to associate death with darkness, but the death of a star often is just the opposite. The Hubble Space Telescope image of a planetary nebula that NASA and ESA just released serves as a reminder that out in the cosmos, even death can be bright, energetic, and beautiful.
The dying star shown in the image on the left is the planetary nebula known as NGC 6565. One day, likely thousands of years from now, our own sun will die in a spectacular planetary nebula, too.
Planetary nebulas have nothing to do with planets, despite their misleading name. They are kind of like smaller-scale supernovas, in that both describe the explosive phase of the death of a star, but the nature of these two death-throes explosions are very different.
When a relatively low-mass star – a category that encompasses stars as large as eight times the mass of our sun – explodes into a planetary nebula, it shoots out all of the star stuff in its outer "envelope." That ejected envelope expands outward, creating the dazzling colors shown in this latest image.
This cosmic light show often continues for around 10,000 years before the gorgeous gases shrink back toward the cooling star at the nebula's center. Eventually, this sprawling and flamboyant display transforms into a modest white dwarf star.
The Ring Nebula, shown below, is the most famous example of a planetary nebula, one which rages on 2,500 light years away – that's practically right next to us when you consider that the Milky Way Galaxy is a staggering 100,000 light years across.
