The star in question generated the first known planetary nebula in a globular cluster, one of more than 100 dense collections of stars that surround the Milky Way galaxy, Hubble researchers said Thursday.
Planetary nebulae are huge clouds of glowing gas that certain kinds of stars emit near death.
They are so named because their shapes reminded 18th century astronomers using primitive telescopes of planetary disks. It's a stage of life for stars at the very end. Because it's hot, it ionizes the nebula to make it shine, like a neon light. While common in some parts of the universe, they remain almost unknown in globular clusters because the clusters possess few stars with enough mass to generate them. It is located in globular cluster M 15, about 40,000 light-years away in the direction of the constellation Pegasus.