Omega Centauri
Can you imagine? Until 1677, Omega Centauri was considered a star (hence its name) and Edmund Halley, at 20, went to Saint-Helen in the south atlantic, with his telescope and discovered to his huge amazment a blob of faint light rather than a bright star.
He immediately saw it must be much bigger than the solar system (he had no idea by how much)! Edmund Halley, being the first with a telescope in the southern hemisphere, must have seen many new things!!!!! He also later identified M13 as the same kind of thing.
Raoul