When hydrogen is used as fuel runs low. Pressure is reduced Labour gravity due to the mass of the sun, the higher voltage. The sun collapse As a result, condemns the central star has a temperature higher than 100 million Kelvin, the reaction thermo-nuclear fusion nucleus of helium nuclei of carbon. At the same time condemns hydrogen pipeline outer helium temperatures rise. Reaction fuse hydrogen into helium, once again, the power is off hugely. The sun grew bigger as 100 times its current size. The pressure increase The outer skin expansion Skin temperature to drop The color will change from yellow to red. Sun becomes a red star, big-called red giant.