The night sky attracts a curious eye with twinkling celestial bodies - stars. How often a wish is made at the sight of a shooting star. Although their number in the Universe is approaching 100 quintillions, scientists still have a question about the lifespan of luminous celestial bodies.
A star called the Sun
In all respects, the Sun is a typical star that illuminates the Earth for about five billion years and will continue to shine as much according to scientific research. The duration of the glow of the Sun is influenced by the amount of fuel in the celestial body.
In fact, thermonuclear fusion reactions occur in all stars, due to which the visual glow of the body is observed. The fusion process occurs as a result of reactions in the hot cores of stars, where the temperature index reaches 20 million ° C (20000273.15 kelvin).
Relative to temperature and distinguish degrees of reactions occurring in the core in many cases due to the color of the star's surface. The coldest stars are red, with a core reaction temperature of up to 3500 K. Yellow stars viewed through binoculars have a core temperature of up to 5500 K, and blue stars - from 10,000 to 50,000 K.
The rate of energy release in a star and its lifespan
Star life begins as a cloud formation of dust and gas. In such a formation, the combustion of hydrogen begins, the production of helium. When the hydrogen burns out completely, the subsequent processes of the stages of the formation of a celestial body start, like the combustion of helium, where heavier elements are obtained as a result.
It is the temperature index of the burning of a star, as well as the gravitational pressure of the outer layers, that affects the rate of energy release by the body, which is directly related to its total life span. The above parameters of combustion and external pressure, followed by a general increase in the mass of a celestial body, increase. Hence, the rate of energy production increases, and hence the observed luminosity of the stars.
Stars with massive cubic weight burn their own nuclear fuel much faster, only for several million years, while being the brightest celestial bodies. Low-mass bodies burn hydrogen more economically and use their fuel more sparingly, so they can live even longer than the Universe. Although the luminosity of low-mass stars is small and the energy release is weak, their life can reach up to 15 billion years.
The life of stars and their generations
The total life span of stars depends not only on size, but also on the initial composition at formation. The first celestial bodies in the Universe lived for only a few tens of millions of years, since they were enormous in size and composed only of hydrogen.
In the cores of such huge and hydrogen bodies, thermonuclear reactions proceeded faster, in which hydrogen was converted into heavier components and helium. Further, the core cools down, since neither temperature nor pressure is enough to process heavier elements, and the star explodes. The remnants after the explosion of such celestial bodies form new, less hot and brighter stars.
A star, like the Sun, belongs to the third generation of yellow dwarf stars of spectral class G. When formed, such stars contain not only hydrogen, but lithium and helium. It will take more than one billion years before the hydrogen fuel for useful life runs out in the example of a star like the Sun, since typical stars are in the middle of their own life path.
