August 10th will usher in the Qixi Festival. On that day, will the Cowherd and Weaver Girl really meet at Queqiao as the legend says? Wang Kechao, director of science popularization at the Purple Mountain Observatory of the Chinese Academy of Sciences, said that folklore expresses the good wishes of the ancients for love, and also entrusts their romantic imagination of the vast starry sky, but in reality, the Cowherd Star representing the Cowherd and the Weaver Girl representing the Weaver Girl have always been "in different places", even on the day of the Qixi Festival, they cannot "meet".
In astronomy, the Cowherd and Vega refer to the two rivers and the first Weaver Girl, respectively. The second drum and the nearby one and three drums are arranged in a similar straight line, as if the cowherd picked a pair of flat shoulders. The Vega One is the second brightest star in the Northern Hemisphere, with four fainter stars around it, arranged in a shape that resembles a diamond, and is considered to be the shuttle of the Vega Girl.
As the main star of the constellation Lyra, Vega is on the "west shore" of the Milky Way, and as the main star of the constellation Aquila, the Cowherd is on the "east shore" of the Milky Way, and the two stars are separated by a "river", about 16 light-years apart. "The distance that is 'walked' in a light year is one light year. For example, if the 'Cowherd' sends a Qixi Festival blessing message to the 'Weaver Girl', it will take about 16 years for the 'Weaver Girl' to receive it. Wang Kechao said that not only that, but the distance between the Cowherd Star and the Vega Star is still increasing, and the distance will be farther in the future.
With the precession of the Earth's axis, Vega was and will still have the opportunity to be our "North Star". The Earth revolves around the Earth's axis, and the intersection points between the Earth's axis and the Earth's surface are the Earth's North Pole and the South Pole, respectively. About 14,000 years ago, the Earth's axis used to point near Vega. Currently, the Earth's axis is pointing towards Gouchen I, now the North Star. In about 12,000 years, the Earth's axis may point again near Vega, at which point the bright star will once again exist as the "North Star".
On the romantic day of Tanabata, how do we look for the Cowherd and Vega? Wang Kechao introduced that at 8 o'clock in the evening in Beijing, for example, if the weather is fine, Vega will appear in the northeast overhead, which is a bright blue and white star. Looking southeast in the direction of Vega, you can see a bright white star, which is the Cowherd Star. Between the Cowherd and Vega is the Milky Way. Let's go find out!
Curator: Liu Xinhui
Reporter: Wang Juejun, Qiu Bingqing
Poster: Xu Zhan
Jointly produced by Xinhua News Agency and Xinhua News Agency Jiangsu Branch
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