Globular cluster
Also called: globular, GC.
A dense ball of hundreds of thousands of very old stars orbiting in a galaxy's halo.
Globulars are among the oldest things in the universe — about 12 billion years old. Each packs up to millions of stars into a sphere a hundred light-years across. The Milky Way has about 150 of them, swarming around its centre like bees around a hive.
In small telescopes they're fuzzy balls; with more aperture and higher power the edges break up into countless pinpoint stars, and the core blazes. Omega Centauri and 47 Tucanae in the southern sky are the greatest; M 13 in Hercules is the northern showpiece.
At the eyepiece
Use high power on a steady night: resolving a globular into stars is all about seeing and a small exit pupil (about 1–1.5 mm).