Whenever we look up at the stars on a clear night, we will see the stars in the sky, and if we do not use astronomical telescopes, we can see more than 6,000 with the naked eye
But in fact, this is only the tip of the iceberg. There are at least 200 billion or more stars in our galaxy, and scientists estimate that in the entire universe, there are even more stars than the sand on Earth combined! It is precisely because of them that all things were created.
Among so many stars, the closest star to us is the Sun, which is a huge celestial body composed of plasma, which can accommodate 130 Earths in volume and 330,000 times the mass of Earth.
But the Sun, though large, is incomparably small in comparison with real stars. For example, Seamount II is 5 million times the volume of the Sun, and Betelgeuse is 700 million times the volume of the Sun. Vy Canis Major, 8 billion times larger than the Sun!
Although the volume and mass of these stars in the universe are large and small, but their formation method is the same, are born from the nebula composed of gas and dust, scientists have found that a huge molecular cloud due to the long-term gravitational action, matter will gather together, when a high-density region appears, a large number of nebulaes will gradually collapse to high-density regions!
Because of the conservation of angular momentum, the nebula rotates faster as it contracts, slowly forming a disc-shaped structure, and in his center, the matter also rises in temperature and pressure as it collapses, and when the core reaches 15 million degrees, hydrogen eventually undergoes a fusion reaction, and in this way, a hot star is born.
Next he will burn steadily, depending on the quality, some may burn for billions of years, some may be up to tens of billions of years!
At this point, many people may wonder why the star burns for so long, and where does its energy come from? The answer is his core!
In the case of the sun, for example, the reason why the sun can burn all the time is that the thermonuclear reaction of four hydrogen atoms converging into one helium atom is constantly happening at the core of the sun! About 600 million tons of hydrogen per second is converted into 596 million tons of helium and releases 4 million tons of hydrogen, and it is these fusions that bring light and heat to the earth.
But the sun doesn't continue to melt, and when he runs out of fuel, it will come to an end. It is estimated that after about 4 billion years, the sun's hydrogen element will gradually deplete, internal fusion will slow down, at which point gravity will begin to prevail, the core energy will not be enough to maintain the hydrostatic balance, and the volume will expand to 200 times, becoming a huge red giant, at which time the earth will be directly engulfed by the red giant.
In the red giant stage, the core of the sun will begin to trigger a new round of nuclear fusion, that is, the process of fusion from helium to carbon, but the carbon due to the fusion conditions are extremely high, when the core of the sun completely forms a carbon ball, it can no longer continue to exert pressure to release energy, and eventually the entire star disintegrates, the material is thrown outward, forming a planetary nebula, leaving only a high-density white dwarf in the center!
And if a star's mass is much larger than the sun, its death process will be more terrible, but also create the cornerstone of life, such as Betelgeuse far away 640 light-years away, he is a star larger than the sun, the mass is about 15 times that of the sun, its internal nuclear reaction is very violent, can be fusion to iron, its death is completely different from the sun, supernova explosions will occur, this is the most violent astronomical phenomenon in the universe, the energy released in a few seconds is equivalent to the sum of the energy released by the sun in its lifetime.
After his death, the core is left with a denser neutron star. A more massive star with a core of more than 3.2 times the mass of the Sun would form a black hole from which no light can escape.
And massive stars can produce heavier elements at the moment of violent explosion, such as gold, silver, and other precious materials, and even elements of life, it can be said that there is no supernova explosion without you, and there is no me. So we are all products of stars. So we have to thank the stars for giving life to the elements that give life to the universe!