If you live in the city for a long time, you will not think that there are more than 6000 stars in the sky

Once upon a time, looking up at the stars and thinking about the mysteries of the universe was one of the greatest joys of childhood. As we grew up, this kind of fun gradually left us. We went out every day and went home. The only thing we forgot was to look up at the night sky and see the stars and the moon in the night sky. Of course, we don’t look at the stars any more because we don’t have time, energy and mood. One of the important reasons is that we can’t see anything even if we look up. The moon is still high in the night sky of the city, but in addition, it is often nothing. On a sunny night, sometimes we can see a few stars, and we can no longer name them. Air pollution and light pollution everywhere in the city make it difficult to enjoy childhood by looking up at the stars. < / P > < p > you who have lived in the city for a long time may have forgotten that when we look up at the stars, there are actually many, many more than 6000 stars. < / P > < p > Yes, we can see 6000 stars all over the sky without any observation equipment, and most of them are the same as the sun. Standing on the earth, the only natural satellite we can see with the naked eye is the moon, the satellite of the earth. However, the satellites of other planets are too small and far away to be seen with the naked eye. < / P > < p > don’t say it is a satellite of a planet. Even the planet itself is not so easy to see. After all, the planet itself does not emit light. The reason why it can be seen by us depends on the reflection of the sun’s light. Of course, we can’t generalize. The brightest star we can see on earth is a planet, that is, Venus, which is the nearest to our earth. It is about 40 million kilometers away from the earth. < / P > < p > among the seven planets in the solar system except for the earth, six are visible to the naked eye, and the only one that cannot be seen with the naked eye is Neptune, which is the farthest away. < / P > < p > the only planets that can be seen with the naked eye in the night sky are the ones mentioned above. In addition, more than 6000 visible stars are all stars. The only star in the solar system is the sun, so we always think that the star is a unique and powerful celestial body. In fact, in the universe, the number of stars is too large to count. < / P > < p > there are about 100 billion to 400 billion stars in our galaxy alone, which is much more than the number of stars that can be seen with the naked eye on earth. However, the more than 6000 stars visible to the naked eye are not all in the Milky way. A star can be seen directly depends on two factors, one is the brightness of the star, and the other is the brightness of the star One is the distance between the star and the earth. The nearest neighbor star is the nearest extrasolar star to the earth, but we can’t see it with the naked eye because its brightness is too low. What determines the absolute brightness of a star? It’s determined by the mass of the star. < / P > < p > the greater the mass of a star, the more intense the hydrogen fusion inside the star, and then it will release more light and heat, and its brightness will naturally be higher. According to the mass of stars, stars are divided into different grades. The stars with the smallest mass are called red dwarfs, followed by orange dwarfs, then yellow dwarfs and blue dwarfs. The sun is a medium mass star, which belongs to the yellow dwarf star in the division of stars, while the neighboring star is much smaller than the sun. It is just a red dwarf star, and a red dwarf star cannot be directly seen by the naked eye in light-year distance. There are hundreds of billions of stars in the Milky way, but there are only more than 6000 stars that we can see directly with the naked eye. The reason is that most of the stars in the galaxy are red dwarfs and yellow dwarfs slightly larger than red dwarfs, which account for about 90% of the total stars in the galaxy. The brightest star we can see in the night sky is Sirius, which is 8.6 light-years away, a blue dwarf much larger than the sun. So what is the farthest star we can see? It’s hip54751. It’s 12000 light-years away from the earth, but because of its huge mass and volume, we can see it directly with the naked eye. The universe is a magical place. The stars all over the sky give birth to all our dreams. Children growing up in the city may never see the scene of stars all over the sky. If you have not seen it, you must go and see it once. Why? Because we should remember to look up at the stars, not at our feet. Privacy Policy

Author: zmhuaxia