Why are there constellations and stars?

Refers to the stars in the sky. In the three-dimensional universe, these stars are not actually related to each other, but in fact, the position of the celestial sphere on the surface of the spherical shell is similar. Since ancient times, people have been interested in the arrangement and shape of stars, and naturally linked some stars with similar positions to form constellations. Constellations play an important role in astronomy; Astrology also uses images of the zodiac 12, but astronomers regard astrology as pseudoscience without using real scientific methods.

Basically, dividing stars into constellations is a random process. Different civilizations have different constellations made up of different stars-although some constellations made up of more conspicuous stars are roughly the same in different civilizations, such as Orion and Scorpio.

The International Astronomical Union divides the sky into 88 official constellations with precise boundaries, so that every star in the sky belongs to a specific constellation. Most of these official constellations are based on the ancient Greek traditional constellations handed down from the Middle Ages, and people divide them into several regions according to the natural distribution of stars in the sky.

Different sizes. Each region is called a constellation. Connect the bright stars in the same constellation with lines to form various figures. According to their shapes, they are named after similar animals, vessels or mythical figures, such as Cygnus and Andromeda. The stars in each constellation are arranged in lowercase Greek letters according to brightness, such as Ursa Major α and Ursa Major β. Constellation is the sum of celestial spaces in an area projected on the celestial sphere. So such a constellation is not accurate inside/outside the Milky Way. Constellation originated in Babylon, one of the four ancient civilizations. About 5000 years ago, a group of Babylonian shepherds lived a nomadic life in Mesopotamia. In their wandering life as shepherds, they still don't forget to observe the twinkling stars in the night sky every day. Over time, they can see the regular changes of time and season from the dynamics of the stars. Every night, they look at the sheep, observe all kinds of stars, connect the brighter stars with each other, associate all kinds of animals, utensils and even gods they believe in from the connected shapes, and name them, creating the so-called constellation. It is said that there are more than 20 constellation names, such as the so-called zodiac 12 constellation, which was born at that time. Since then, the Babylonians have continued to divide the sky into many regions and put forward new constellations. However, at that time, constellations were of little use, and even fewer were discovered and named. The constellation 12 on the ecliptic was originally used to measure time, not to express people's character as it is now. Around 1000 BC, 30 constellations have been proposed. The Tigris River and the Euphrates River flow from northwest to southeast and flow into the Persian Gulf, so they are also called "two river basins". After the culture of the two river basins spread to ancient Greece, it promoted the cultural development of ancient Greece. Ancient Greek astronomers supplemented and developed the Babylonian constellation and compiled the ancient Greek constellation table. In the 2nd century A.D., Ptolemy, an ancient Greek astronomer, synthesized the astronomical achievements at that time and sorted out 48 constellations. Connect the main bright stars in the constellation with imaginary lines, imagine them as images of animals or characters, and give them appropriate names in combination with fairy tales. This is the origin of the constellation name.