What stars are there in the Milky Way?

Question 1: What stars does the Milky Way contain? The Milky Way is the star system where the solar system is located, including120 billion stars, a large number of star clusters and nebulae, and various types of interstellar gas and dust. Its total mass is 654.38+04 billion times that of the sun. Most stars in the Milky Way are concentrated in a oblate sphere, which is shaped like a discus. The protruding part in the middle of the oblate sphere is called the "nuclear sphere" with a radius of about 7000 light years. The center of the core ball is called "silver core" and the periphery is called "silver disk". There is a bigger sphere outside the silver disk, where there are fewer stars and less density. It is called "Silver Halo" with a diameter of 70,000 light years. The Milky Way is a spiral galaxy with a spiral structure, that is, it has a silver center and two spiral arms, which are 4500 light years apart. The rotation speed and period of each part of it are different because the distance from the silver center is different. The sun is about 23,000 light years away from the galactic center, and it orbits the galactic center at a speed of 250 km/s with a period of about 250 million years.

About 90% of galactic matter is concentrated in stars. There are many kinds of stars. Stars can be divided into five star families according to their physical properties, chemical composition, spatial distribution and motion characteristics. The youngest extreme group I stars are mainly distributed on the spiral arms in the silver disk; The oldest extreme group II stars are mainly distributed in silver halos. Stars often gather in clusters. In addition to a large number of binary stars, more than 1000 clusters have been found in the Milky Way. There are also gases and dust in the Milky Way, accounting for about 10% of the total mass of the Milky Way. The distribution of gas and dust is uneven, some gather into nebulae, while others are scattered in interstellar space. Since 1960s, people have discovered a large number of interstellar molecules, such as carbon monoxide and H2O. Molecular clouds are the main places where stars form. The core of the Milky Way, the silver nucleus or silver nucleus, is a very special place. It emits intense radio, infrared, X-ray and gamma-ray radiation. Its nature is not clear, and there may be a giant black hole, and its mass is estimated to be tens of millions of times that of the sun. Little is known about the origin and evolution of the Milky Way.

Question 2: How many stars are there in the Milky Way? The number of stars in the universe is calculated according to the number of stars in the Milky Way. According to the present technical means, it is impossible for us to see every star in the Milky Way. Visible light telescopes can observe stars with a radius of 5,000 light years around the sun, while the radius of the Milky Way is 50,000-60,000 light years, the sun is about 33,000 light years away from the center of the Milky Way, and the farthest Milky Way star is 90,000 light years away. According to the current inference, there are about 400 billion stars in the Milky Way, with a plus or minus error of 50%. So the number of stars in the Milky Way is 200 billion to 600 billion. There are 1000 billion to 200 billion galaxies similar to the Milky Way in the universe. If at least 200 billion stars are used to calculate the number of stars in the long river system, the calculated number of stars in the universe is 2× 1022 ~ 4× 1022, that is, 20 trillion ~ 40 trillion.

Question 3: How many sun-like stars are there in the Milky Way? The Milky Way is the star system where the solar system is located, including120 billion stars, a large number of star clusters and nebulae, and various types of interstellar gas and dust.

Question 4: What stars are there in the Milky Way? List three. Every star in the sky is a star. Except Jin Mu, water, fire and the earth, they are the solar system.

Question 5: What is the center of the Milky Way? Why are there so many stars there? ! What is the center of the Milky Way?

At first, people tried to peep into the secrets of the center of the Milky Way with optical telescopes. Although people have the ability to make optical telescopes bigger and bigger and see farther and farther, they still can't see the true face of the center of the Milky Way. Later, I found out the reason, because there is a lot of dust near the silver heart, which can block people's sight like white fog or yellow sand.

In recent decades, the rapid development of infrared astronomy, radio astronomy and X-ray astronomy has provided astronomers with new observation tools and means to explore the mystery of the center of the Milky Way, because infrared, radio waves and X-rays can all pass through the dust barrier. In this way, infrared rays, radio waves and X-rays from the galactic center, like messengers from the galactic center, can bring us some important information about the galactic center.

Through observation, scientists found that infrared radiation, radio emission radiation and X-ray radiation from the center of the Milky Way are much stronger than those from other regions. It is speculated that the center of the Milky Way may not be a simple cluster of stars, and it is difficult to draw a conclusion about what it is. By 197 1, two British astronomers pointed out that the center of the Milky Way should be a "black hole" with a certain mass (in fact, the "black hole" they said should be a black hole. As mentioned above, a black hole is a solid celestial body, but because of its large mass, even light can't escape under the great gravity, and we can't see it, so it is called a black hole. A black hole is a special celestial body with a virtual body. For solid matter, it not only has no mass and gravity, but also has no space. In order to distinguish them, we put the words "black hole" in quotation marks to show that its true and accurate name should be black hole. The following is similar). They predict that if their hypothesis is correct, there should be a strong radio source at the center of the galaxy, and the radiation emitted by this strong radio source should accelerate synchronously. A few years later, people really found such a strong radio source emitting strong synchronous radiation in the center of the Milky Way. It is Sagittarius A, the largest radio source in the galaxy. Some people judge that Sagittarius A is likely to be a massive "black hole", but others think that it can only be regarded as the best candidate for a massive "black hole" for the time being, and it cannot be concluded.

Recently, American astronomers have speculated that there may be two "black holes" in the center of the Milky Way. It is said that there may be a medium-sized "black hole" in the center of the Milky Way, which is thousands of times the mass of the sun. It is dragging some young stars to the huge "black hole" in the center of the Milky Way. It is speculated that its motion mode is around a giant "black hole" with a period of 100 years, and it will be swallowed up by the giant "black hole" sooner or later, thus making the latter bigger. Not long ago, some astronomers said that they also found three giant "black holes" near the earth, located in Virgo and Aries, 5 to 654.38 billion light years away from the earth. Although 1 light-year is equivalent to about 10 trillion kilometers, according to the measurement standards of cosmic objects, this distance is equivalent to neighbors.

Unusually, the mass of these three "black holes" is 50 million to 654.38 billion times that of our sun. These astronomers believe that such a huge mass is rare in a "black hole". There are only about 20 known "Big Macs" of the same kind, and the mass of most other "black holes" is only several times that of the sun.

Scientists have different views on how these "black holes" are formed. Rich Stone, a researcher at the University of Michigan in the United States, believes that these three large "black holes" may be the remnants of quasars, which are aurora materials. In such a large area of Mars, the illumination is equal to 1 trillion suns. He also pointed out that quasars appeared before the formation of most stars in the Milky Way. If it is finally confirmed that the three giant "black holes" come from quasars, they may appear at the peak of quasars' age, that is, about 1 100 million years after the birth of the universe. If so, whether there are galaxies or "black holes" first becomes the next question that astronomers need to study.

NASA announced that they have also detected a medium-sized "black hole" in the universe. This discovery not only fills the "missing link" in the study of the evolution of the "black hole" family, but also helps to deeply understand the basic astronomical problems such as the formation of galaxy structure.

It is reported that there are two medium-sized "black holes" detected this time, which are stored separately. & gt