The last of its kind?

Stellar streams consist of groups of stars moving in orbit together. They are usually remnants of small galaxies that were absorbed by larger galaxies or former star clusters. The Phoenix stream discovered four years ago is the latter. It was, as researchers show in an article in Nature, once a globular cluster, and a very special one at that.

Globular clusters are special objects in themselves. Imagine the night sky full of gleaming stars shining much brighter than the brightest planets in our ...