When I was a child, I lived in the countryside, there was no entertainment, the weather was hot in the summer, and after dinner, everyone liked to lie outside the house to cool off, especially when the weather was clear, you could often see the stars in the sky. The most impressive is the Big Dipper, when the elderly in the countryside called them "spoon stars", because the order of these seven stars looks like a spoon.
When we looked up at the stars, most of the stars we saw were stars from the Milky Way, which were relatively close to us, because of the influence of the Earth's atmosphere, these stars sometimes looked shimmering like blinking eyes.
What are the stars in the sky?
More than 400 years ago, when Galileo first pointed his telescope at the starry sky, he found four small bright spots around Jupiter moving around Jupiter, knowing that Copernican heliocentrism was not yet mainstream at that time. It was also from that time that human beings really began to explore space, and gradually realized the vastness of the universe.
Because of gravity, the celestial bodies in the universe attract each other to move, the main celestial body members are stars, a star with a huge mass, it can make many small bodies move around themselves, such as the Earth and seven other planets. The solar system is located on a spiral arm of the Milky Way, 16,000 light-years from the silver core, and the sun carries the entire family around the center of the milky way.
There are about 200 billion stars in the Milky Way, but in the 200,000-light-year diameter Milky Way galaxy, only those that are closer to us can be seen by the naked eye, and there are about 6,000 stars visible to the naked eye throughout the day.
In addition to most of the stars in the sky, there are a few visible planets, they belong to the solar system, such as Venus, Jupiter, etc., of course, human probes can sometimes be observed, such as the International Space Station and China's space station, etc., the difference is that these probes are moving in the night sky.
What are the seven stars of the Big Dipper? How far away are we?
Among the more than 6,000 stars visible to the naked eye, the Big Dipper is relatively well-known, of course, only in the northern hemisphere can see their existence. Because the special shape can be particularly noticed by human beings, and the Big Dipper can also guide the ancients to more easily grasp the cycle of the four seasons, such as the ancient book "The Crown of the Osprey": the bucket handle refers to the east, the world is spring; the bucket handle guide, the world is summer; the bucket handle refers to the west, the world is autumn; the bucket handle refers to the north, and the world is winter.
01, Tianshu: also known as Ursa Major α star or more domineering wolf star, its absolute magnitude 0.2, apparent magnitude 1.79, so visible to the naked eye. Located 124 light-years from the earth, it is the farthest from the earth among the seven stars of the Big Dipper, the first in the spoon image, and the second brightest star in the big dipper. Unlike several other stars, the Celestial Hub is an orange giant, which also means that it has reached the end of its life.
02, Tianxuan: also known as ursa major β star, known as giant gate star in ancient China, about 80 light years away from us, the apparent magnitude is about 2.37, so it is visible to the naked eye. It is the second in the spoon image at the mouth of the spoon.
03, Tianji: is the γ star A in the constellation Ursa Major, also known as Lu Cun star, 83 light years away from us, in the Big Dipper seven-star spoon image in the spoon mouth of the third, visual magnitude 2.44, is the sixth of the seven stars of the Big Dipper.
04, Tianquan: Ursa Major δ star, in ancient times it has another name that is the famous Wenqu Star, 80.5 light-years away from the earth, the apparent magnitude of 3.3, from the spoon handle number of the fourth, but also the darkest of the seven stars of the Big Dipper. In addition, Tianquan has two companion stars, with apparent magnitudes 10 and 11 respectively, so it is not visible to the naked eye.
05, Yuheng: Ursa Major ε Star, known in ancient China as Lianzhen Star, the apparent magnitude of 1.77, so it is the brightest of the seven stars of the Big Dipper, and it is also the 31st brightest star visible to the naked eye throughout the day, 82.6 light-years away from The Earth.
06, Kaiyang: Ursa Major ζ star, it is essentially a quadrangle star system composed of binary star systems, which are 78 light-years away from Earth.
07, shake the light: ancient China called it the broken army star, in the Big Dipper seven stars is the third bright star, the whole day of the 39 bright stars, the apparent magnitude of 1.86, is the big dipper seven stars on the spoon handle of the end of the one, 103 light years from the earth.
In fact, we can see that the Big Dipper looks like stars in a system framework, but in fact, their distance from the Earth is uneven, in other words, they are not on a plane, and some are not even a star, but because it is too dark for the naked eye to observe!
Say at the end
Stars are also not constant, if the time scale is too large, the position of these stars in the sky is changing, because these stars also have their own speed, the current Big Dipper seven stars look like a spoon shape, the past Big Dipper seven stars and the future Big Dipper seven stars will not be a regular spoon shape.
Text/science black hole, image source network intrusion deletion.