There are only twelve constellations

Why is there only 12 constellation now?

As far as I know, there are 12 constellations, namely Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. These constellations have been used in the western astrological tradition ever since.

But in recent years, the discussion about the number of constellations mostly stems from an article entitled "You may not know, our number of constellations may have expired" [1]. It is mentioned in this paper that the ecliptic guardian stars of four common constellations, Cancer, Libra, Scorpio and Aquarius, have shifted, which makes astronomers put forward a new concept of constellation and add 13 constellation "Ophiuchus". However, the 12 constellation in western astrology has not changed because of this, and the traditional 12 constellation is still used.

Generally speaking, the number and definition of constellations are jointly formulated by astrology and astronomy, and different fields have different standards and interpretations.