From the Super Mario Wiki
A star in Bowser's Galaxy Reactor.
Stars are massive spheres made from a substance known as plasma. They produce heat and radiation in outer space. In the Mario series stars are produced by matured Lumas. Bowser utilized the power of stars in Super Mario Galaxy for his reactor. In the Real World stars are made when a cloud of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements collapse together. Usually a planet can be found orbiting around a star. While the stars in the Real World are much bigger than any planet, some stars in the Mario series are roughly only the size of a house, which is impossible in the Real World due to its physics. When stars die or collapse, they usually produce Black Holes.
[edit] Notable Stars
