Geographical Constellation _ Constellation Region

Do you know which constellations are in the northern sky?

I believe that most people's understanding of constellations is limited to the twelve constellations seen in leisure magazines. In fact, these twelve constellations are only a part of the 88 constellations in the whole day.

signs of the zodiac

There are 88 constellations in the whole day, and the standard number of constellations was formulated by the International Astronomical Union in 1930. The constellation you see in leisure magazines is the famous zodiac. These constellations are just above the ecliptic, which is the only route for the sun in the sky, so it is called the zodiac. And which constellation you belong to depends on which constellation the sun was in when you were born. But all this happened 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. And because the swing period of the earth's axis is 26,000 years, the position of the ecliptic in the sky is also changing. This periodic oscillation of the earth's axis is called precession.

In this way, every two thousand years, the time for the sun to reach each house will be pushed back by about one month. Now the vernal equinox is not in Aries, but has retreated to Pisces. In addition, the ecliptic now not only passes through the twelve constellations, but also praises the thirteen constellations of Ophiuchus. Press the comparison chart on the left to find the difference between the constellation that the sun passed through when you were born and the traditional constellation.

The origin of constellations

In ancient times, people had to know the seasonal changes in detail for animal husbandry and agriculture. They noticed that the arrangement of stars in the sky is different in different seasons. In order to memorize and spread this knowledge conveniently, they use their imagination to connect the chaotic stars in the sky, which is the origin of the constellation.

Western constellation

Western constellations originated in ancient Greece, and the earliest mention of constellations was in a poem Phaenomena written by the Greek poet Aratus in 270 BC. As can be seen from this poem, the word constellation was known to mankind before Aratus.

The constellation mentioned by Aratus has no stars at all near the south celestial pole. This may be because these stars are all below the horizon of the region where the constellation name is located. From these unmeasurable horizons, we can infer that the people who named the constellations probably lived at about 36 north latitude, that is, south of Greece and north of Egypt, where Babylon and Sumer were located.

Due to the precession of the earth's rotation, the north and south poles of the earth will deviate periodically with time. According to calculations, this unexplored celestial sphere was just above the south celestial pole in 2000 BC, which was also the time when ancient Babylonians and Sumerians lived.

Based on this, we have great reasons to believe that Greek constellations originated in ancient Babylon and Sumer. The knowledge about constellations later spread to Egypt and was known by some Greek scholars who lived there at that time.

In A.D. 150, the Greek scientist Ptolemy compiled an astronomical book named "Astronomical Table", which summarized the astronomical knowledge of the Greeks at that time, including the names of 48 constellations and 1022 stars, and the estimation of their luminosity.

China's star

In fact, there was a similar constellation concept in ancient China. In ancient China, there were stars and officials, among which the twenty-eight palaces with three walls and four images were the most important.

In ancient China, in order to observe and record the movements of special celestial phenomena such as the sun, the moon and the five stars, the sky near the north celestial pole and the top of the head was divided into three areas, called "three walls", namely Ziweiyuan, Taiweiyuan and Tianshiyuan respectively, while the area around the equator of the ecliptic celestial sphere was divided into four star areas, named after animals as four elephants, namely black dragon, white tiger and suzaku respectively. Some people say that it is related to the totem of primitive tribes, others say that it represents seasons, and others say that the ancients imagined bright stars as animal shapes and named them after auspicious animals. As for the four colors, it seems to be related to the five elements (gold, wood, water, fire and earth) that prevailed in ancient times. The orientation of the four elephants is based on astrology seen in the morning before and after the vernal equinox. At this time, Suzaku is in the south sky, the dragon in the east, the white tiger in the west and the horizon in the north.

Because the coverage of each district of the Four Elephants is too wide, each district was later subdivided into 7 chapters, that is, 28 chapters. Some huts are named after the horns, hearts and tails of the four elephants, which refer to the horns, hearts and tails of dragons respectively. From west to east, 28 hostels were named Jiaokang, Bullfighting Women's Virtual Dangerous Wall, Kuibi God and Liujing Ghost Easy in turn, with different spans every night. The stars at night will be named after the night. For example, antares in Scorpio is located in the heart, and Betelgeuse in Orion is located in Betelgeuse.

The name of the Twenty-eight Hostel was first found in, and all the names of the Twenty-eight Hostel were first found in Lu in the Spring and Autumn Period. It takes a long time to form a complete system, and its name and scope have evolved and adjusted many times in past dynasties. 1978 in the tomb of Zeng Houyi excavated in Leigudun, Sui County, Hubei Province, there is a lacquer box cover with the ancient name of 28 lodging houses written on it. It is inferred that the system of 28 hotels

The number of modern constellations

A total of 88 constellations in the northern and southern hemispheres were officially named by astronomers. This was established by 1930 International Astronomical Union. The names of these constellations include 14 names, 9 species of birds, 2 species of insects, 29 species of land and water animals, some mythical animals and some inanimate objects. It is worth mentioning that the shapes and names of most constellations are nothing like each other. Probably when the ancients named constellations, they tended to use symbolic methods to name constellations as their favorite animals or mythical figures.

Also, the stars in the same constellation rarely have anything to do with each other, but visually they are very close and the distance from us is very different.

The shape of the constellation is not immutable. Although these stars seem to have been fixed in the same position for the past 3000 years, in fact they have been moving relative to the sun at a speed of up to 10 kilometers per second.

Because they are too far away from us, it is difficult for us to observe the change of their position unless there are 30 thousand years. Because of this action, 50,000 years later, bucket handle of the Big Dipper will bend his hips even more than today. Although the shape of the constellation will change with time, we probably won't change the name of the constellation because of it.

Four seasons constellation

In addition, according to the different seasons and the time when individual constellations reach zenith, the 88 constellations are roughly divided into four groups, namely, spring constellations, summer constellations, autumn constellations and winter constellations.

Why do the starry sky change in spring, summer, autumn and winter? This is because when the earth revolves around the sun, the side facing away from the sun is the starry sky we can see in the season that night. As the earth rotates around the sun, it gradually changes its position, so the starry sky in the background slowly changes.

For example, in February 1, we went to watch the stars. After dusk, the constellations we see on the western horizon are Aquarius, Pegasus and Pisces, while Perseus, Aries, Auriga, Taurus and Lahu are high in the sky.

By the beginning of May, we were watching the stars in the same place. After dusk, the constellations on the western horizon have become Perseus, Taurus and Lahu, and the constellations in the middle of the sky are Cancer, Leo and Ophiuchus.

In early August, at the same time and place, Cancer, Leo and Ophiuchus have sunk to the western horizon. The constellation of Zhongtian has been replaced by Aries, Big Dipper, Serpent and Five Immortals.

After several months of continuous observation, you will find that every three months, the constellation of Zhongtian will move to the western horizon.

Generally speaking, you can see the starry sky in three seasons in one night. For example, at dusk in midsummer, we can see the constellation of spring hovering on the western horizon, while the constellation of summer is high in the sky. At dawn, the autumn sky is at the zenith.

Of the 88 constellations, we can only see some of them. Other constellations will never reach the horizon. To see these constellations, we must go south of the equator.