Information about Altair 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 16 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 a son and a daughter of Altair-Heguyi and Heguyi. Legend has it that the cowherd and a daughter are chasing the weaver girl on the 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 is roughly the same as the celebration activities in the Northern Song Dynasty recorded in Wu's Dream Record and Wulin Biography. 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. Altair is a very important planetarium in the field of astrology mathematics in ancient China. "Shuo Wen Jie Zi" says that "everything is also; Cows are big things, and the number of heaven and earth begins with cows, so they don't talk with cows. " The ancients believed that the sun and the moon started from Altair, turned left from Altair and ended at Beidou. The sun and the moon start from here, and all the magic numbers between heaven and earth start from here. Therefore, everything in the world comes from cows. Ancient people observed astronomical phenomena. If a meteor appears near Altair, they think that the number of days will change and the world will be uneasy. They think that all the changes of tricks, luck and fortune between heaven and earth originate from Altair, and all the changes of numbers can be found in Altair. Astronomers at the University of Michigan in the United States combined the light emitted by four telescopes and finally successfully photographed the surface details of Altair. This is the first time that scientists have clearly photographed the surface structure of a star similar to the sun. John Monnier, an astronomer at the University of Michigan, and his graduate student Zhao Ming led an international team of astronomers to make a detailed observation of Altair with the CHARA interferometric telescope array in Mount Wilson, California. This observation used four of the six telescopes in the mirror array, which were about 270 meters apart. After combining light with so-called optical interferometry, the observation effect is comparable to that of a very large telescope with an area equivalent to a football field, so the resolution of the Altair photos taken is extremely high, even about 100 times finer than the clearest photos taken by the Hubble Space Telescope. Other research groups have used this technology to take pictures of the surfaces of other stars, but those stars are hundreds of times larger than the sun and Altair. This observation by the University of Michigan captured the surface details of another main sequence star outside the solar system for the first time, which is a major breakthrough in the history of observation. The main sequence star refers to a star with stable thermonuclear fusion. Most visible stars in the sun and the night sky belong to the main sequence stars. Harold McAlister, an astronomer at Georgia State University who participated in this observation, pointed out, "For us, this is just the beginning. There are countless main sequence stars waiting for us to observe, and being able to take photos of their surfaces will provide a lot of information for future research work. " Altair is the brightest star in Aquila, which can be clearly seen by naked eyes in the night sky in the northern hemisphere. This star is hotter and younger than the sun, and its diameter is about twice that of the sun. The rotation speed of Altair equatorial region is as high as 654.38+0.027 million kilometers per hour, which is about 60 times the rotation speed of the sun! Therefore, Altair is not a nearly perfect sphere like the sun, and its "waist circumference" is obviously enlarged and becomes a flat ellipsoid. As early as 1924, astronomer Hugo von Zeipel predicted that rapid rotation would make the equatorial region of the star protrude. He also predicted that the brightness of the protruding part would decrease, leading to the so-called gravity darkening phenomenon, because it was farther away from the core of the star and the temperature would be lower. This photo of Altair seems to confirm his prediction, because the equatorial region really looks dark. However, after careful analysis, Monnier pointed out that the darkening degree of the equatorial region exceeded the prediction of the standard model, which indicated that the existing theoretical model had defects and needed further revision. Zhinv 1 is a bright star in Lyra, whose 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 Vega. Declination 18h47m, declination 38 degrees 47 minutes. Vega's diameter is 3.2 times that of the sun, its volume is 33 times that of the sun, its mass is 2.6 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 26.5 light years away from the earth. More than 65438+300,000 years ago, Vega was once the North Star. Due to the precession of the earth's axis, the current Polaris is the A star of Ursa minor. But in 6.5438+0.2 million years, Vega will return to the prominent position of Polaris. Next to Vega, four stars form a small diamond. Legend has it that this small diamond is a shuttle used by the weaver girl to weave cloth. While knitting, the Weaver Girl looked up at the Cowherd (Hegu II) and her two sons (Hegu I and Hegu III) on the east bank of the Milky Way with deep affection. Modern astronomical observations show that the entire solar system is moving towards Vega at a speed of 19 km per second. It is reported that Vega is spinning around the black hole at a speed of 19 km per second. Vega is the brightest star in Lyra (Alpha Lyra) and the fifth brightest star in the whole day, second only to arcturus. In summer in the northern hemisphere, Vega can be seen near the zenith, 25.3 light years away from the earth. Because the apparent magnitude of Vega is close to zero, many professional astronomers will use Vega as the standard for photometric determination. Vega, Tsukuya II (Altair) in the eagle and Tianjin IV in Cygnus form the famous "Summer Triangle". If you think of it as a right triangle, Vega is a star that forms a right angle. The spectral classification of Vega is A0V, and the temperature is a little higher than Sirius A1V.. It is still in the main sequence star stage, emitting light and heat by condensing hydrogen in the core into helium. In addition, the mass of Vega is 2.5 times that of the sun. The higher the mass of a star, the faster it consumes fuel, and the energy released per second is equivalent to 50 times that of the sun. Therefore, the life span of Vega is only 65.438 billion years, which is one tenth of the life span of the sun. It is determined that Vega rotates once every 12.5 hours, the whole star is flat, and the equatorial diameter ratio is 23%. References:

Baidu knows that Altair and Vega are two stars like the sun, and they can also shine by themselves. The official name of Altair in China is Heguji; It combines with several other stars to form a constellation called Skyhawk. The official name of Vega in China is Vega I; It and several other stars form a constellation called Lyra. The names and divisions of constellations were introduced from the west. Altair and Vega are far away from us! Altair 16 light years, Vega 27 light years. The distance between them is also very far, which is 16 light years. That is to say, the fastest light and electricity, from Altair to Vega, have to run nonstop 16 years, not to mention other means of transportation. Suppose the Cowherd and the Weaver Girl really live on these two stars, and they want to make a phone call or send a telegram to say hello to each other. This long-distance call will take 16 years one way! In addition, the surface temperature of Altair reaches 8000 degrees Celsius, while Vega is even higher, reaching 1 1000 degrees Celsius. Vega is bigger than Altair in size. The diameter of Vega is three times that of our sun, while the diameter of Altair is 1.6 times.