I heard that only stars can shine in the universe, why can Venus also shine

A quasar is the brightest object in the universe, and it is 1,000 times brighter than a normal galaxy. For objects of such great energy, quasars are incredibly small in their huge energy. Compared to galaxies with a diameter of about 100,000 light-years, quasars have a diameter of about 1 light-day.

Astronomers generally believe that it may be caused by the fact that matter is pulled into a supermassive black hole at the center of the galaxy, which releases a large amount of energy (eruption rays). These distant quasars are thought to have been "lit up" when material was channeled into the black hole at the center of the main galaxy to add "fuel" when the early galaxies had not yet evolved to a more stable stage.

Only stars emit light, it is true, the light of Venus is caused by the reflection of the sun's light, and all the planets of the solar system appear bright, but in fact they are caused by the reflection of the sun's light.

All stars in the universe can emit light, and when astronomers were studying the universe, they named the planets that could shine and heat as stars, and the planets that could not shine and heat could not be called stars. A star must have four conditions of its own: it can emit light, it can carry heat, the light on the star can promote the photosynthesis of plants, and the star can provide a reference for nearby celestial bodies, because the star emits light, so it can provide this reference.

There are many luminous stars in the universe, and these stars are innumerable, and their distribution is very sparse. But people will wonder why so many luminous stars exist in the universe, but the universe is cold, and the night sky seen by humans is still dark. That's because there are many celestial bodies in the universe besides stars, which are black and cannot emit light.

With the study of the universe more and more deeply, black holes were later discovered, and some scientists proposed that black holes should also be classified as a kind of stars, but although black holes have high energy, they are not a plasma that can emit light. Scientists have wanted to change the definition of a star, believing that the definition of a star should be composed of high-temperature plasma gases, which can rely on internal nuclear fusion to release energy, resulting in the phenomenon of luminescence and heat. For such a redefinition, black holes still do not meet one of the criteria for a star.

Scientists believe that the development of stars to the main sequence star stage, the continuous evolution of the star has entered the final stage is about to end, and perseverance will not undergo nuclear fusion, that is to say, there is no nuclear fusion energy inside the star. But the black holes in the universe, their masses are not equal, and there are stellar black holes in the black holes, and this kind of stellar black holes are much larger than stars, with much greater mass and great energy, so scientists believe that black holes can be classified as stars, but this statement has not been recognized at present.

Not.

When we usually talk about stars, we are only talking about stars in the main sequence stage, when a star has finished the main sequence stageAlthough they don't have an internal fusion reaction, but they are still at the stellar level. For example, black dwarfs, white dwarfs, stellar black holes, etc., they belong to the stellar class but do not emit light.

Yes. At night, the luminous stars we can see are stars, and there are many stars that cannot be seen with the naked eye. The closest star to us is the Sun.

All stars in the universe emit light on their own, because the process of nuclear fusion is constantly taking place on the star, so it emits light and heats.

At the beginning of the 20th century, biologists based on the eminent scientist Newton's theory of relativity published a correlation of mass and energy that aided astronomy. Scientists have solved the question of why stars shine.

Originally, the internal structure of the star was at a temperature of 10 million degrees Celsius, and chemicals could react at such a high temperature. The reaction of the lighter molecular nuclei into the old heavy atoms damages a part of the mass in this process, and at the same time releases a great deal of energy.

Therefore, this kind of energy is transmitted from the inside to the outside by diffusion, from the surface of the star to the indoor space, so that it shines in the cosmic space for a long time. The internal structure of planets is much cooler than that of stars, so they themselves are not, and those that can release great energy are not easy to shine.

The mass of the planet is also much smaller than that of the star, even Jupiter, which has the mass of the planet of the solar system, is less than one thousandth of the mass of the sun, so the energy obtained by the planet's attractive convergence is not easy to make its internal structure high enough to produce a thermonuclear reaction.

Billions of tons of hydrogen are converted into helium every second, which is the same reason as a flame burns and emits light, and stars are large fireballs that burn violently, releasing huge amounts of heat and light energy.

A star is a natural nuclear reactor in the universe, and violent nuclear fusion reactions are being carried out all the time, and the reaction is to release a large amount of energy to radiate outward, most of which are invisible to the human eye, including thermal radiation, ultraviolet radiation, and so on. The light wave radiation that can be seen by the human eye is also among them.

The mass of a star is so great that even if it were to carry out large-scale nuclear fusion all the time, the matter inside it would be enough to support tens to tens of billions of years. But there are times when stars burn out, and that's when the star goes out, and the star will decay into a red giant star that will change violently, and after a higher loss and intensity of fusion, it will completely extinguish in less than eleven years, turning into a white dwarf star, a neutron star, and even a black hole.

The internal temperature of the star is more than 10 million degrees Celsius, and at such high temperatures, the matter undergoes nuclear fusion reactions. During the release process, the star loses a portion of its mass and releases a huge amount of energy. This energy has been included in various types of sparkling in electromagnetic radiation.

It can be seen that the reason why stars can emit light is because the star is constantly undergoing violent nuclear fusion reactions inside the star, and the starlight it emits is the product of nuclear fusion, which is electromagnetic radiation from the inside of the star.

Stars are all gaseous planets. On clear and moonless nights and in areas without light pollution, the average person can see more than 6,000 stars with the naked eye, and with the help of telescopes, hundreds of thousands or even millions of stars can be seen. It is estimated that there are about 1500-400 billion stars in the Milky Way, and the Sun, the host star of our solar system, is a star.

Stars shine mainly because the reaction of nuclear fusion produces a lot of light and heat, and the stars we see at night are basically stars.

I think the reason why stars can emit light is because of the reflection of sunlight, and most of the stars we see at night are stars, and today these stars are reflected millions of years ago.

Stars shine because they are burning themselves, such as the sun, and most of the planets that are not stars seen at night and reflect the light of the stars.

First of all, you have to understand what stars are and what planets are, and once you know the difference between them, you will naturally understand.

What is Star?

Stars are gradually formed through the cosmos nebula. Nebulae gradually began to rotate and gather due to gravity and other very special conditions, and then gradually began to form nuclear fusion. Therefore, stars are stars that can emit light and heat themselves through nuclear fusion.

What is Planetary?

When the star is formed, it is not very close to the star, and the remaining nebula material around the star gradually solidifies and cools, and gradually forms a planet, and the one that enters from the center will solidify into a solid planet because of enough material; The original separation from the center will lead to the formation of a gas planet due to a lack of matter.

So you can see the difference between a star and a planet.

Therefore, the planet does not have enough matter and mass to undergo nuclear fusion, and naturally it does not heat and glow.

All stars are undergoing nuclear fusion reactions, and luminescence is a manifestation of the energy they radiate outward. There are no fusion reactions on the planets so they don't emit light, they can only reflect the light of the stars.

In layman's terms, there is a nuclear reaction in the star, which will release energy, and part of it will be released in the form of light. And some planets can also emit light, such as Jupiter, the interior of the earth is also hot and light, as long as the earth's crust is cooled, wrapping up hahaha.