# How big is the largest star in the universe? Let the scientists tell you the answer, and you’ll understand after reading it

The universe is so vast that there are so many planets like the earth. The diameter of the earth is 12756 kilometers. Before human beings walked out of the earth, it felt that the earth was so big. In ancient times, people wanted to go from the south pole of the earth to the north pole by carriage, which might not be twice as long. But with the development of science and technology, with the rapid means of transportation, suddenly feel the earth smaller.

Living on the earth, you can never feel how big the earth is, but when human beings walk out of the earth and stand in the universe to see the earth, they will know the vastness of the universe. The earth is not even dust. The planets larger than the earth in the solar system are Jupiter and Saturn. There are countless planets larger than the earth outside the solar system, and there are many super earths.

Compared with the sun and stars, the earth is even smaller. The diameter of the sun is 109 times that of the earth, and the volume of the sun is 1.3 million times that of the earth. In the eyes of human beings, the sun is so big, it occupies 99.86% of the total mass of the solar system, is the real boss. But the sun is just an ordinary star in the universe. In the family of stars, it can only be regarded as short, not big. There are too many stars bigger than it.

So how big is the biggest star in the universe? At present, the largest star in the universe observed by scientists is uy in scutellus. It is actually a red super giant. The so-called red super giant is actually the expanding volume of a star at the end of its life. Its diameter is about 2.376 billion kilometers, and it can hold 4.5 billion suns. It takes nine hours for light to rotate around it, while it only takes 14.5 seconds for light to rotate around the sun. This shows how huge this red supergiant is.

If the sun is replaced by uy, five of the eight planets in the solar system will disappear, and mercury, Venus, earth, Mars and Jupiter will be engulfed by uy. Although the size of this super red giant is very huge, its mass is not high, only 32 times the mass of the sun, and its surface temperature is not as high as that of the sun, mainly because its internal hydrogen nuclear fuel is almost consumed, and its nuclear fusion reaction is much weaker.

Although the star looks huge, its mass and temperature are not high. However, its brightness is very high, about 340000 times that of the sun. It is one of the brightest stars observed by scientists at present. It is precisely because of its extremely high brightness that it can be observed by astronomical telescopes. Otherwise, we will not find it at all. It is too far away from the earth.

The life span of this red supergiant is coming to an end, with only 10-50 million years left. For a star with a life span of about 10 billion years, tens of millions of years is the real end of its life. When it is completely extinguished, it will explode to form a supernova. With its volume and mass, it will eventually collapse into a black hole.

The life span of a star is about 10 billion years. At the end of its life, it can have three Fates. The small one will become a white dwarf, the medium one will become a neutron star, and the larger one, like shield uy, will evolve into the dominating black hole of the universe. It seems that the strong is always the strong, even if the end of life, there will be another stronger state.

Our sun is also a star. It has been burning for 5 billion years, with about 5 billion years left. After 1 billion years, the sun will begin to expand outward, and it will engulf the orbits of mercury and Venus. At that time, the earth will be the closest planet to the sun. The temperature of the earth will rise sharply and gradually become unable to survive, and human beings will have to leave the earth to live on other planets.

When the Sun continues to expand until it runs out of fuel, it will eventually become a white dwarf at the end of its life. It is still an ordinary star and can not be compared with neutron stars and black holes. The reason is that the sun is only a weak existence in the family of stars and can not evolve into a powerful celestial body after death. However, white dwarfs are also very beautiful. For human beings, we hope that the sun will become a white dwarf, because in this way, the solar system can still exist and will not disappear.

If a star becomes a powerful object like a black hole, the solar system will not be engulfed by it. Some people may be more curious, what kind of stellar system will this red supergiant be in? Will there be intelligent civilizations like human beings? If so, what will their fate be? In fact, this question is not easy to answer.

Because it is so far away from the earth, our telescopes can only see this bright star, but can’t see the stars revolving around it. However, scientists believe that this red supergiant must have been a star many times larger than the sun 5 billion years ago. Such a huge star can attract many planets to revolve around it. There must be planets in its star system, and there may also be living planets like the earth.

If this stellar system once had a life planet, which could give birth to intelligent life and civilization at a very early time, now that the star has come to the end, the life planet may have been engulfed by its continuous expansion. If this alien civilization has the ability of interstellar navigation, it may have left this galaxy to live in other galaxies. Of course, there is another bad situation, that is, the birth of intelligent life in this stellar system is relatively late, and it may not be able to walk out of the planet now, which may be very bad.

However, the life span of this star is at least 10 million years. Even if the development speed of this alien civilization can be compared with that of human beings, 10 million years is enough to develop interstellar technology and leave the galaxy for other galaxies. It is different from the solar system. If the solar system is at the end of the sun, some planets give birth to intelligent life, but it has no ability to go out of the solar system, it can also choose to live on planets far away from the sun, such as Uranus and Neptune.

Even if the sun goes out at last, the explosion will only turn into a white dwarf, and the solar system will not disappear. However, after the explosion of the red supergiant, it will turn into a black hole, and it is impossible not to leave the galaxy. Therefore, the solar system is very lucky. However, human beings have been born for millions of years, and the speed of scientific and technological development is also very fast. In another billion years, the pace of human beings may have already covered the whole galaxy.

At that time, the solar system was only a dispensable existence, and the earth was only the birthplace of human beings. Even if the solar system could not survive, human beings on the earth could go to other galaxies to live. There were many planets in the galaxy like the earth, and some of them were better than the ecological environment of the earth. On the contrary, with the continuous development of science and technology, the environment of the earth became worse and worse Maybe we can’t wait for the day when the sun turns into a red giant, we have to leave the earth, because the earth can’t adapt to human existence.