A Globular Cluster

Youthful NGC 362Globular clusters offer some of the most spectacular sights in the night sky. These ornate spheres contain hundreds of thousands of stars, and reside in the outskirts of galaxies. The Milky Way contains over 150 globular clusters, and NGC 362 is one of the more unusual ones.

As stars make their way through life they fuse elements together in their cores, creating heavier and heavier elements—astronomers call anything further up the period table than helium a “metal”—in the process. When stars die, they flood their surroundings with the material they have formed during their lifetimes, enriching the interstellar medium with metals. New stars that form from the remnants of older stars contain higher proportions of metals than their older relatives. The stars in NGC 362 contain a surprisingly high metal content, indicating that it is younger, second generation stars. Most globular clusters are much older than the majority of stars in their host galaxy, but NGC 362 bucks the trend, with an age lying between 10 and 11 billion years old. That makes them newbies compared the average age of a star in the Milky Way, 13 billion years.

Image Credit: ESA / NASA