Dream constellation analysis _ dream constellation

Astronomical data about Altair and Vega

Hegu II is the alpha star of Aquila, commonly known as "Altair". It is a very famous bright star in the sky in summer and autumn, and it is silvery white. It is 0/6.7 light years away from the Earth/kloc-0, its diameter is 0/0.6 times that of the sun, its surface temperature is about 7000℃, its luminous power is 8 times greater than that of the sun, and its visual magnitude is 0.77. It faces Vega across the Milky Way. According to an ancient legend, the Cowherd and the Weaver Girl met at the Magpie Bridge on July 7th. In fact, the Cowherd and the Weaver Girl are 14 light years apart. Even on the most powerful rocket in modern times, they never met after hundreds of years. The two dark stars on both sides of Altair are Altair's two sons-Heguyi and Heguyi. Legend has it that Cowherd and his two sons chased Weaver Girl on a pole.

As early as the Han Dynasty, the Book of Rites said in Zheng Xiao: "The weaver girl travels eastward in the middle of the month, and the stars also cover the story." That is to say, at least in the Han Dynasty, people have noticed the running law of Vega in the sky, especially in July. "Historical Records Biography of Tianguan" says that Zhinu is the grandson of Tiandi. , that is, the origin of Tiansun. Astrology: It says, "Morning glory is the name of heaven." The cowherd is a cowherd, and the river drum escaped later. The story of the meeting of the Cowherd and the Weaver Maid on July 7th can be found in Fu Xuan's "On July 7th, the Cowherd and the Weaver Maid will meet in Tianhe". This legend may have originated in the early Eastern Han Dynasty.

In the poem of Wang Xiangqi in the late Qing Dynasty, he wrote: "The fellow villagers raised talents, and the grandson married the river drum. A hundred-year match ended in a hurry, and the tears were always silent." What he sees is a mismatch. What he yearns for more is: "The riverside is as red as the sky, and Jin Yuanyang does not fly alone." According to the Chronicle of Jingchu in Zonggu of the Southern Dynasties, in Jianghan area at that time, on the night of the seventh day of July, women in every household tied colored silk thread and left very thin needles. Some people use gold, silver and copper as needles, put melons and fruits in the yard and pray for wisdom from Vega God. If spiders weave webs on melons and fruits, it is considered as a sign of the arrival of Vega God. That is to say, on the night of July 7, there is not only the significance of meeting the Cowherd and the Weaver Girl, but also the significance of praying for wisdom from the Vega God. As the textile goddess in folklore, Vega symbolizes the diligence and wisdom of ancient working women. On this night, ancient women made sacrifices to her by tying colored silk thread, hoping to get the source of ingenuity from her, so the night of July 7 is also called "Begging for Cleverness Festival", which is an enterprising festival.

Later, in the Northern Song Dynasty, Mr. Meng Yuan wrote in "Dream of China in Tokyo" that Tanabata was particularly lively when the Northern Song Dynasty was at its peak. "Three or five days before Tanabata, horses and chariots were all over the city, and Luo Qi was full of festivals, but the lotus did not open. Everyone is good at making double-headed lotus flowers, and they will be carried back after playing for a while. Passers-by often can't put it down. " On the evening of the 7th, there were many colorful buildings in your house, which were called' Chocci House'. Paving up the past, grinding and drinking music (note), flower melon, wine moxibustion, pen and inkstone, needle and thread, or children's poetry scissors, the girl is smart, which is called' seeking cleverness'. " . The Qixi Night in Lin 'an in the Southern Song Dynasty, recorded in Wu's Liang Lumeng and the meticulous Old Stories of Wulin, is roughly the same as the celebrations in the Northern Song Dynasty. Compared with the Southern and Northern Dynasties, the activities of Begging for Qiaojie Festival in Song Dynasty were more colorful. I like Jojo Festival, which is not only a part of China's ancient multi-folk culture, but also a festival that inspires wisdom and evokes the reverie of love.

Weaver Girl 1 is a bright star in Lyra, and its scientific name is Lyra-α. It is one of the most famous bright stars in the summer night sky. Usually, people call it Vega. In the west, it is called "Queen of Summer Night".

In China, the fairy tale of Cowherd and Weaver Girl is widely circulated: According to legend, in Guqiong, there lived a loving couple. Later, when his wife died, the husband felt very lonely and secretly prayed that he could ascend to heaven as soon as possible so that he could meet his wife. After her husband died, the crane really took him to heaven and became a morning glory. Unfortunately, the husband and wife are separated by the Tianhe River, one in the east and the other in the west, so they can't meet at ordinary times. Heavenly Emperor was deeply moved by them, and let them cross the bridge built by magpies on the seventh day of July every year. This is what people often say when the Cowherd and the Weaver Girl meet at the Magpie Bridge.

In ancient Greek and Roman mythology, Vega was called "Lula" and "Lila", meaning harp. [Lila] hence the name.

Vega's diameter is 3.2 times that of the sun, its volume is 33 times that of the sun, and its surface temperature is 8900 degrees Celsius, showing a bluish white color. It is one of the three brightest stars in the northern hemisphere sky, about 26 light years away from the earth.

More than 654.38+300,000 years ago, Vega was once the North Star. Due to the precession of the earth's axis, the current Polaris is Xiaoxiong-Alpha. But in 6.5438+0.2 million years, Vega will return to the prominent position of Polaris.

Next to Vega, four of them formed a small diamond. Legend has it that this small diamond is a shuttle used by the weaver girl to weave cloth. While weaving, the Weaver Girl looked up at the Altair (Hegu II, Eagle-α) and her two sons (Hegu I and Hegu III) on the east bank of the Milky Way.

Modern astronomical observations show that the entire solar system is moving towards Vega at a speed of 19 km per second.

Far away from Vega is He Gu Er, a first-class bright star on the east bank of the Milky Way, whose scientific name is Aquila-α, commonly known as Altair. Like Vega, it is a very famous bright star in the summer night sky.

Altair is about 16 light-years away from the earth, its diameter is10.6 times that of the sun, its surface temperature is about 7000 degrees, it is silvery white, and its luminous power is 8 times greater than that of the sun. Altair rotates very fast, about 7 hours, so its shape is oblate. It is calculated that its equatorial radius is 0.5 times of 65438+ polar radius.

There is a dark star on each side of Altair, which is called Hegu I and Hegu III respectively. Together with Hegu II, it is called "Hegu Samsung". The river drum is like a long shoulder pole, so people call it "the shoulder pole star". Legend has it that Cowherd (Hegu II) is in the middle of the pole, carrying his two sons Hegu I and Hegu III at both ends, and has been chasing the Weaver Girl.

In the summer sky, three bright stars, Altair, Vega and Tianjin IV, Cygnus-α, form an eye-catching triangle, which is called "Summer Triangle". Altair is located at the southern end of the triangle. This big triangle is an important manifestation of finding summer constellations. In late summer, it was observed in China that the triangle and its nearby galaxies rose to the zenith at midnight.

In the middle of summer and autumn, Altair and Vega are high in the sky, which is a good season to observe them.