"Roundabout Morning Glory Star, Kyaukgyao River Han Girl". Tanabata is coming, are cowherds and Vegas going to meet through the Queqiao Bridge? "Actually, no, 'two people' have always been 'long-distance love'." Wang Kechao, director of science popularization at the Purple Mountain Observatory of the Chinese Academy of Sciences, said that the meeting between the cowherd and the weaver girl is a beautiful vision of love by the ancients, and it also pins on the romantic imagination of the ancients on the vast starry sky.
Wang Kechao explained that Cowboy Star and Vega Star are two stars, and the distance between the two stars is about 16 light years. "In layman's terms, the light year 'walks' is a light year, that is, the cowboy star calls Vega and says 'I love you', and the other party will not hear it until 16 years later."
As the second brightest star in the Northern Hemisphere, Vega is known in some areas as the "Princess of Summer Nights". There are four small stars around Vega, arranged in a shape somewhat like a diamond, and are regarded as "weavers". Due to its rapid rotation, Niu Langxing is ellipsoidal in appearance, like a "big uncle with a big belly". As the main star of Lyra, Vega is on the "west bank" of the Milky Way, and as the main star of Aquila, The Cowboy Star is on the "east bank" of the Milky Way, and the two stars are facing each other across the "river".
Looking up at the summer night sky and witnessing the "long-distance love" of Cowherd Star and Vega Star, there is a "super light bulb" Tianjin Four Star. The four stars of Tianjin are the main stars of the constellation Cygnus, and it is said that the Emperor of Heaven crossed the Milky Way, hence the name "Tianjin". Tianjin Four Stars is one of the brighter stars in the summer sky, it and the Cowherd Star, Vega Star in the summer night sky to form a triangle, known as the "Summer Triangle", is the symbol of the summer starry sky.
"Throughout the year, the stars we see at night are different." Wang Kechao said that a solar day averages 24 hours, while the average star day is 23 hours, 56 minutes and 4 seconds, so every day the star will rise about 4 minutes earlier than the previous day, and as time accumulates, the time for stars to rise will be earlier and earlier. In the summer evening, the stars of Niulang, Vega and Tianjin rise high and are easy to observe, but in the autumn evening, they have begun to set in the west.
Producer: Zhao Cheng
Producer: Hu Qinghai
Planner: Liu Xinhui
Reporters: Qiu Bingqing, Zhu Xiao
Poster Maker: Xu Zhan
Edit: Chonghai
It was jointly produced by Xinhua News Agency and Jiangsu Branch of Xinhua News Agency
Produced by Starry Sky Studios