https://www.cnet.com/news/hubble-telescope-sees-oodles-of-stars-in-one-wild-space-place/

Globular clusters are spherical collections of stars. Messier 3 is a bit unusual, though. It's packed with a whole bunch of variable stars, ones that change in brightness over time. Scientists have spotted 274 of these twinklers in Messier 3. 

As long as we're throwing around cool space terms, here's another one: "blue stragglers." These stars are bluer and more luminous than their brethren. They look younger than their neighbors, but they're really more like vampires.