The formation time of the sun is determined by two methods: the age of the sun on the main sequence belt, confirmed by the computer model of star evolution and primitive nuclear synthesis, is about 4.57 billion years. This is very consistent with the radioactive dating method that the oldest material of the sun is 4.567 billion years. The sun has reached middle age in the evolution stage of its main sequence. At this stage, nuclear fusion is to condense hydrogen into helium at the core.
Every second, more than 4 million tons of matter are converted into energy in the core of the sun, producing neutrinos and solar radiation. At this speed, up to now, the sun has converted about 100 earth mass matter into energy, and the total time spent by the sun on the main sequence belt is about 100 billion years.
Extended data
The sun is a yellow dwarf (G2V spectrum). The life span of a yellow dwarf is about 654.38+000 billion years. At present, the age of the sun is about 4.57 billion years old. After about 5 billion to 6 billion years, almost all the hydrogen in the sun will be consumed, and the core of the sun will collapse, leading to an increase in temperature. This process will continue until the sun starts to condense helium into carbon.
Helium fusion produces less energy than hydrogen fusion, but the temperature is also higher, so the outer layer of the sun will expand and release part of the outer atmosphere into space. When the process of turning to new elements is over, the mass of the sun will drop slightly, and the outer layer will extend to the current orbit of the earth or Mars.
Reference source: Baidu Encyclopedia-Sun