Why did the 12 constellation become the 13 constellation?

Because of the change of the earth's axis, the movement of the solar system and the movement of the stars themselves, the position of the zodiac constellation is very different from that before 2000.

The correct date after the change is as follows:

Shepherd: 04/ 19 ~ 05/ 13

Taurus: 05/ 14 ~ 06/22

Gemini: 06/23 ~ 07/2 1

Cancer: 07/22 ~ 08/ 10

Lion: 08/11~ 09/16

Virgo: 09/17 ~10/31

Libra:11/01~1/23

Scorpio:11/24 ~11/29

Snake Man:11/30 ~12/17

Sagittarius:12/18 ~ 0119

Capricorn: 0 1/20 ~ 02/ 17

Water bottle: 02/ 18 ~ 03/ 12

Pisces: 03/ 13 ~ 04/ 18

What constellation are you?

Do you know that the constellation you belong to is just above the route (ecliptic) that the sun must pass through in the sky (* * * has twelve constellations), so it is collectively called the zodiac? The sun was in your sign when you were born. ....

But this was more than two thousand years ago!

More than two thousand years have passed, and the dates of the twelve constellations are no longer consistent with the astronomical phenomena.

As the earth's axis oscillates in a period of 26,000 years, the position of the ecliptic in the sky also changes. In this way, every two thousand years, the time for the sun to reach a certain palace will be delayed by about one month. In addition, the ecliptic now passes not only through the twelve constellations, but also through the thirteenth constellation of Ophiuchus.