Lead
Since ancient times, people have had a special curiosity about the universe, and without any evidence, they believe that the earth is the largest star in the universe.
But with the continuous progress of science and technology, people's understanding of the universe is also constantly updated, from the discovery that the earth is not the largest planet, to the initial belief that the sun is the largest star in the universe, and then to the realization that there are stars larger than the sun, and even larger black holes.
The huge celestial bodies in the universe seem to be constantly challenging human cognition, and people are constantly challenging the universe, so what is the largest star in the universe, and what is the largest celestial body?
1. The Milky Way.
In human cognition, the Milky Way is the largest celestial body within human reach, a celestial system consisting of 10 trillion stars and countless planets, as well as other celestial bodies.
In the universe, the Milky Way is also a huge celestial body, but among the celestial bodies of other star systems, the Milky Way is only the second.
In the Milky Way, there is also an extremely amazing star, this star is the UY object of the constellation Aquila, which is also the largest supergiant known to mankind and one of the largest stars known.
The radius of this object is about 1.3 billion kilometers, which is 1,700 times that of the Sun, and if the position of the Sun is replaced by a UY object, the surface of the UY object will touch the Earth's orbit.
The size of the UY object is also extremely large, which can hold 1.8 billion suns, and although the UY object is large, it is not the largest object in the universe.
At first, scientists thought that the UY object was just an unusually large star, but after studying its brightness and mass, it was found that its mass was close to the limit of the star, and if it was larger, it would go to the orbit of a neutron star.
Neutron stars are much smaller than stars, so only a black hole larger than a neutron star can reach the size of a UY object, which also means that the mass of the UY object is much larger than originally predicted.
After the collapse is over, the mass of the UY object will not exceed 50 suns, but scientists predict that the mass of the UY object will reach 120 suns, which means that the mass of the UY object is 120 times that of the sun.
2. UY celestial bodies.
The UY object is one of the largest known stars and the third largest known.
In the universe, the size and mass of stars are directly proportional, and a star smaller and more massive than the Sun does not exist.
And if a star is larger than the Sun, then it is at least larger in mass, and the diameter of the UY object reaches the size of 1708 suns, so its mass is also 120 times that of the Sun.
In the universe, the second largest star is the giant Magellanic Nebula's Shang Star, which is 150 times more massive than the Sun, and a star with the same mass as the Shang Star has not yet been discovered.
So the size of the UY object is already the largest known celestial body, and in the universe, if a star is very massive, then it will produce a nuclear fusion reaction in the core region, produce more energy, and be able to consume fuel faster.
So UY objects will soon be nearing the end of their life cycle, and will soon explode to produce new matter, which may eventually form a larger black hole.
In the universe, there is an even larger celestial body, that is, the black hole, which was once considered the largest object known to date, although it is not large, but the mass is unusually huge.
The volume of a black hole cannot be measured due to the absence of solid matter, but the volume of a black hole can be calculated by the extent of the black hole's influence.
After light is subjected to the gravitational pull of a black hole, it cannot illuminate the surrounding bodies, so people can use this principle to calculate the volume of a black hole.
The volume of the black hole calculated by this method is called the Schwarzschild radius, which is the horizon radius of the black hole, and is also the outermost edge of the black hole.
According to the latest data, the largest black hole known to mankind is the Ton618 black hole, which has a Schwarzschild radius of 1 light-year and a mass hundreds of times that of the Sun, and the volume of the black hole is likely to be much larger than the Schwarzschild radius.
3. The largest celestial body in the universe.
In the universe, black holes are the largest celestial bodies, and their volume is also the largest celestial body known to mankind.
In terms of the volume of the black hole, Huck once mentioned in the paper that the mass of the black hole is inversely proportional to the temperature, and the temperature of the black hole will be quite cold.
Therefore, the largest black hole is the hottest object, and the smallest black hole is the hottest object.
This is also the thermal radiation theory proposed by Hack for the temperature of black holes, that is, under the action of gravity, black holes will shoot particles out of the edge of the black hole's event horizon, and when it flies away from the black hole, it will become abnormally hot, so the temperature of the black hole will decrease with the continuous radiation heat of the black hole.
In terms of the volume of supermassive black holes, Huck also put forward a conjecture, that is, the volume of supermassive black holes will gradually decrease with the increase of mass.
This also explains to a certain extent why people cannot find a super large black hole, because these black holes will be relatively small, so for humans, it is difficult for humans to detect black holes by surrounding celestial bodies, and can only judge the existence of black holes by the orbits of the surrounding stars.
Although human exploration of the universe has made some progress, human beings still do not know enough about black holes in the universe, which is also a strange celestial body, which challenges human understanding of the laws of nature.
It is precisely because of the existence and characteristics of black holes that people have more curiosity about the universe.
epilogue
At present, people's exploration of the universe is in its infancy, and with the continuous development of science and technology, it is believed that human beings' understanding of the universe will continue to be updated.
We will also continue to challenge ourselves on the road of exploring the universe to discover larger and more exotic objects, and perhaps there are other celestial bodies in the universe that we do not know about, but we have not yet discovered them.