To everything existing the term is measured, it concerns as well stars. Including such star as the Sun thanks to which life on the planet Earth is possible. And date of approach of the end interests many people.
In comparison with other stars the Sun looks quite modestly, belonging to the class of so-called yellow dwarfs. Temperature of its surface is about 6000 wasps. Such stars (spectral class G) live about 9-10 billion years while the hydrogen which is contained in them is processed into helium. When reserves of hydrogen run low, there comes the last stage of their life. The star begins to be cooled quickly, temperature of its surface falls approximately about 3000 wasps that corresponds to the red stars belonging to spectral class M. At the same time its overall dimensions sharply increase. The star kind of swells, becoming much more, sometimes in several hundreds of times.
Many stars which on classification concern to red giants are known to astronomers. For example, a star of Betelgeuse in the beautiful constellation of Orion on diameter almost in 500 times more our Sun! Approximately the same sizes at the red giant by the name of Antares - the brightest star in the constellation of the Scorpion. It appear suddenly some of these stars on the place of the Sun, life on Earth instantly would stop. As their external border would pass further an orbit of our planet.
Alas, exactly such destiny, most likely, also expects Earth. Astronomical observations and physical and mathematical calculations demonstrate that with very high probability our Sun at the end of the course of life will become red giant. Also it is not important any more whether it then will absorb Earth or it will only appear quite close from it. Even in the second case temperature on the Earth's surface will increase to such an extent that biological life will become impossible. The fact that similar accident happens still very at a distant day can serve as a consolation. By calculations of astrophysicists the Sun exists about 5 billion years. That is it is in blossoming of the forces, having reached only a half of a course of life. Prior to the future cataclysm still there will pass not less than 4 billion years. So so far inhabitants of Earth cannot worry. And in the distant future if interstellar travel become ordinary business, probably, it will be possible to find other planet suitable for life, and already on it to begin a new terrestrial civilization.