In 1930, in order to unify the complicated division of constellations, the International Astronomical Union divided the sky into eighty-eight formal constellations with precise boundaries, so that every star in the sky belonged to a specific constellation. These include 29 constellations in the northern sky, 12 constellations in the ecliptic, 47 constellations in the southern sky, and 88 constellations.

Since ancient times, humans have connected groups of stars with characters or objects in their myths, calling them "constellations." Constellations are a means of determining the direction of the sky in almost all civilizations, and are widely used in the field of navigation. The division of constellations is completely artificial, and different civilizations have different divisions and naming. There has never been a uniform and precise boundary for constellations. Until 1930, in order to unify the complicated division of constellations, the International Astronomical Union divided the sky into eighty-eight formal constellations with precise boundaries, so that every star in the sky belonged to a certain constellation. specific zodiac sign.

Extended information:

If the vast universe is regarded as a celestial sphere, then the 88 constellations in the universe divide the entire celestial sphere into two parts: the northern celestial sphere and the southern celestial sphere. According to whether most of the area of ??each constellation is in the northern sky or in the southern sky, it is called a northern constellation or a southern constellation respectively. According to this division method, there are 29 northern constellations, 47 southern constellations, and the other 12 are zodiac constellations.