<s>[INST] Can a star cool down enough and become a giant planet? [/INST] 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.</s>\ <s>[INST] How is a brown dwarf formed? What makes it different from other dwarf stars? [/INST] Brown dwarf stars form in a similar way to other stars, through the collapse of a molecular cloud. However, unlike other stars, brown dwarfs do not have enough mass to ignite hydrogen fusion in their cores, which is what makes a star shine.

Other dwarf stars, on the other hand, are stars that have a mass roughly between that of a brown dwarf and the Sun, and do sustain hydrogen fusion.</s>