Constellation English

Constellation introduction:

In order to facilitate Taoist astrologers to recognize stars, people divide several regions with different sizes according to the natural distribution of stars in the sky, and each region is called a constellation.

Connect the bright stars in the same constellation with lines to form various figures. In shape, they are similar to animals and utensils. There are nearly 6,000 stars visible to the naked eye, each of which can only be classified as a constellation, and each constellation can be identified by the shape of a bright star.

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.

Let every star in the sky belong to a specific constellation. Most of these official constellations are based on the ancient Greek traditional constellations handed down from the Middle Ages. Constellation plays an important role in astronomy, and astrology also uses the image of the zodiac. However, if astrology does not use real scientific methods, it will generally be considered as pseudoscience.

It seems that the movement of the constellation with the celestial sphere is caused by the movement of the earth itself, in which the rotation and revolution of the earth are the most obvious changes in the starry sky. Due to the rotation of the earth, the starry sky background rotates once a day around the celestial axis; The starry sky also changes slowly with the seasons. A year has passed, and the starry sky is almost the same as it was a year ago.

The rotation axis of the earth's rotation also has a long-term motion, called precession, with a period of about 25,765 years. This movement causes the periodic drift of the North Pole in the background of stars, which is called precession in astronomy. A cursory observation of the constellation in a short time can ignore this movement.

The stars are moving at high speed. The motion of stars can be decomposed into the radial velocity of their connection direction and the self-nature perpendicular to it, in which the self-nature will change the apparent position of stars in the starry sky. Because the star is too far away from the earth, it can generally be considered that the position of the star in the sky is fixed.

Because the apparent positions of the sun and planets relative to the earth are not fixed with the positions of the background stars on the celestial sphere, they periodically pass through the 13 constellation on the ecliptic. In astrology, it is often described as "Mercury is in Scorpio". However, there are only twelve constellations in astrology, and they are equally divided.