So you bought a telescope to look at everything the universe has to offer. You’ve explored the various craters and maria of the Moon plus the planets, comets, and stars. What should you look at next?
Stars form in groups as giant gas clouds collapse inward and compress the matter into dense, hot clumps. The process of stars exploding and creating gas clouds and gas clouds coalescing back into new stars is ongoing. So anyone with a small telescope can go outside anytime and observe clusters of young stars and nebulae — interstellar gas clouds. A fine open cluster of young stars is the Pleiades, a large, dipper-shaped group in the constellation Taurus. Visible during late fall and winter, the Pleiades is composed of six bluish-white stars bright enough to see without telescopic aid. But try it with a telescope: you’ll see several hundred stars.
The other type of star cluster, a globular cluster, is typically a spherical ball of old stars lying outside our galaxy’s disk. A fine example is M15 in Pegasus. Viewed with binoculars, this collection of perhaps half a million stars appears as a tiny, fuzzy disk of gray light. A backyard telescope at high power reveals a soft glow composed of thousands of stars, a few of which appear resolved toward the cluster’s edge.