The Pleiades Star Cluster
The Pleiades, has lots of names. It is also known as Seven Sisters, Subaru, Corn Maidens, Seven Gurus, and The Tiny Dipper. More remarkably the Pleiades are both a constellation and a star cluster. Star cluster and constellations are seldom the same thing. The stars that make up constellations are all of different ages and different distances and have no actual relation to one another except that we humans have connected these same stars with imaginary lines for millennia. The stars that form star clusters were all born at the same time and in the same place, from huge clouds of dust and gas called star-birth nebulae. Gravity concentrates and compress dust and gas into ever denser spheres until the hydrogen atoms begin to fuse, creating helium atoms, creating an outward current of energy, and subatomic goo. These chaotic cauldrons of nuclear fusion are known as stars. As more and more stars ignite their combined emissions of stellar wind blow the unused dust and gas deeper into space, clearing out the neighborhood, until only the star cluster is left behind.