Complex sentence: Omega Centauri or NGC 5139 is a globular cluster of stars discovered by Edmond Halley in 1677 to be orbiting our galaxy, the Milky Way.
Split into simpler sentences: Omega Centauri or NGC 5139 is a globular cluster of stars discovered by Edmond Halley in 1677. It orbits our galaxy, the Milky Way.