Yes, a star can turn into a planet, but this transformation only happens for a very particular type of star known as a brown dwarf. Some scientists do not consider brown dwarfs to be true stars because they do not have enough mass to ignite the nuclear fusion of ordinary hydrogen. At the same time, some scientists do not consider brown dwarfs to be true planets either because they typically sit at the center of a solar system, just like a star. A brown dwarf is a strange object with a mass that is greater than the biggest regular planets (i.e. above 13 times the mass of Jupiter) and less than the smallest regular stars (i.e. below 80 times the mass of Jupiter). Although a brown dwarf does not have enough inward gravitational pressure to ignite the nuclear fusion of regular hydrogen, it does have enough to ignite the nuclear fusion of heavy hydrogen (deuterium). Early in the life of a brown dwarf, the nuclear fusion of its heavy hydrogen releases large amounts of light and heat. As a result, a young brown dwarf glows like a regular star. Despite its name, a brown dwarf that is still glowing does not appear brown. Rather, it appears magenta or reddish orange. Despite beginning life as a star, a brown dwarf quickly uses up its heavy hydrogen, goes dark, cools, and spends the rest of its life as a planet.