CLUSTERS AND NEBULAS
The plane of our galaxy is a stellar crucible in which coalescing clouds of dust and gas give rise to stars and star clusters by the millions.
The raw material of stars can be found in nebulas—tenuous clouds of dust and gas. Stars that condense from the same nebula may become bound by each other's gravity into an open cluster. For a few hundred million years, they move together through the Milky Way like a school of fish. Eventually, tidal forces and interactions with other interstellar clouds disperse the stars.