Proxima Centauri and the Sun are both main sequence stars, but Proxima Centauri is a red dwarf and the Sun is a yellow dwarf. Based on the information you charted, compare the characteristics of red dwarf stars and yellow dwarf stars.
Sun is younger then proxima centauri as it is a red dwarf star whereas sun is a yellow dwarf. We now this as stars need hydrogen to burn and the older they get they get more red.
