Brightest globular cluster

The brightest globular cluster in the sky is Omega Centauri in the southern constellation of Centaurus (The Centaur). With an apparent magnitude of 3.6 it is easily visible to the naked eye, resembling a hazy star. Omega Centauri is a cluster of several million individual stars, located in a halo of around 140 such clusters which surrounds our galaxy (The Milky Way).  It is around 17,000 light years from Earth. Omega Centauri was often mistaken for Halley's Comet on its last return to the inner Solar System in 1986.