The sun enters this constellation at the vernal equinox-the constellation where the sun is at the vernal equinox.

The relationship between the zodiac signs

Different from the zodiac

Although the names of the zodiac signs are the same as those of the 12 constellation near the zodiac signs, they are essentially different. The zodiac indicates the position of the sun on the ecliptic, and the size of each constellation is fixed. It's all 30 degrees, and the time when the sun enters each house is basically fixed. On March 2 1 every year, the sun comes to the vernal equinox and enters Aries Palace. Around June 22, I came to the summer solstice and entered the Cancer Palace. Before and after September 23, I entered Libra Palace. 65438+came to the winter solstice around February 22 and entered Capricorn Palace.

However, this was not the case before 2000, because under the gravity of the sun and the moon, the rotation axis of the earth did not point to the same position in the sky, but turned around in the sky. This phenomenon is called precession. Due to precession, before 2000, the sun was located in the above four positions of Aries, Cancer, Libra and Capricorn. Different from the ecliptic, the 12 constellation near the ecliptic has different sizes. For example, the width of Pisces is 49 degrees, while the width of Cancer is only 2 1 degree. 12 constellation is not necessarily located on the ecliptic, but distributed within 8 degrees on both sides of the ecliptic.

Relationship with the 24 solar terms

It also reflects the position of the sun in its orbit (ecliptic). There are 12 zodiac signs in the west, and there are 24 solar terms in China, among which western missionaries play an important role. China and 24 solar terms were first determined by "equal division method", that is, the 365 days of a year, 5: 48: 46 (tropical year) were divided into 24 parts on average, thus determining the solar terms. But the speed of the earth's rotation is fast or slow, which is inconsistent with the longitude. At the end of Ming Dynasty and the beginning of Qing Dynasty, missionaries Tang Ruowang and Xu Guangqi invented the method of "fixing qi" according to the method of dividing the degrees of the ecliptic which was introduced to China in Sui and Tang Dynasties but was not paid attention to, that is, taking spring as the starting point and longitude of the ecliptic every 30 degrees as a palace, that is, taking spring as the starting point and longitude of the sun every 15 degrees as a solar term. This makes the division of solar terms more accurate, and at the same time, based on the twelve meridians in China (the degree of the ecliptic in solar terms is an even multiple of 15), the time division of the ecliptic is also more accurate. Taking the rising intersection of the ecliptic and the celestial equator as the starting point, at 0 degree of the ecliptic, that is, about 2 1 in the solar calendar on March, the sun passes through this point (vernal equinox) and enters the zodiac Aries Palace at the same time, and so on, every two solar terms correspond to one zodiac palace. In other words, the starting point of the zodiac is exactly the same as the twelve qi in the twenty-four solar terms.

There is indeed a fixed correspondence between the Chinese zodiac and the twenty-four solar terms in ancient China. A more accurate statement should be: the sun always runs to the same house in the same solar term.

The following is the correspondence between the two: Zodiac 24 solar terms Zodiac 24 solar terms Aries Palace Spring Equinox Qingming Libra Palace Autumn Equinox Cold Dew Taurus Palace Grain Rain Long Summer Scorpio Palace Early Frost beginning of winter Double Uterus Xiaoman Mangma Palace Xiaoxue Cancer Palace Summer Solstice Capricorn Palace Winter Solstice Minor Cold Lion Palace Summer Solstice. Beginning of autumn Aquarius Palace, Great Cold, beginning of spring Room, Women's Palace, Summer Vacation, Dew, Pisces Palace, Rain thorn, because the zodiac and the 24 solar terms are all measured, and the standard is the accuracy of the sun on the ecliptic. However, it should also be pointed out that as far as we know today, the zodiac and the twenty-four solar terms record the ecliptic degree of the solar apparent motion in astronomy, which are all solar calendars in calendar science; But the twenty-four solar terms are used for agricultural production, while the zodiac is used for astrology. This is the difference.

Zodiac related parameters Chinese noun symbols Latin possessive abbreviation area star number Aries? Aries ari44150 Taurus? Taurus Tauri Tau 797 125 Gemini? Gemini Geminorum Gem 5 14 70 cancer? Cancer Cancri Cnc 506 60 Leo? Leo Leo 947 70 Virgo? Virgo Vir 1294 95 Libra? Libra Lib 538 50 Scorpio? Scorpio Sco 497 100 Sagittarius? Sagittarius Sagittarius SGR 867 1 15 Capricorn? Capricorn Capricorn I CAP 4 1450 Aquarius? Aquarius AQR 980 90 Pisces? Pisces