The binary star in the Big Dipper.

Hello, landlord, this star is Kaiyang. Its companion star is close to it, but it is visible to the naked eye.

The order of the Big Dipper from spoon head to spoon bean is: Shu Tian, Tian Xuan, Tianji, Tian Quan, Yuheng, Kaiyang and Yaoguang. Kaiyang is the star in the spoon tail or bucket handle. It is a typical physical binary star visible to the naked eye and the only star in the whole day that can be recognized as a physical binary star by the naked eye.

Kaiyang's physical partner is commonly known as "Fu" among the people. The ancients found it very close to the sun long ago. In the Qing Dynasty, China astrology incorporated it into astrology works, and its scientific name was enlightened. There is an old saying in China that "you can't see the salary by looking at the details". Westerners say that "you can see the auxiliary star, but you can't see the moon", all of which refer to the auxiliary star. When ancient Arabs recruited soldiers, they used it as a test star to test soldiers' eyesight. Only those who can tell that Kaiyang is a binary star can be considered qualified in eyesight and as a soldier.

As for the giant gate star, it is actually Shu Tian. Shu Tian is the official name of astronomy in Chinese, but in the fortune-telling disk (that is, the fortune-telling disk in the hands of street fortune tellers), the names of the Big Dipper have changed, namely Giant Gate, Wolf-greedy, Lucun, Wen Qu, Lian Zhen, Wu Qu and Pojun. So the giant gate is Shu Tian. But it's an unofficial name.

The Big Dipper is very bright and can be seen in cities with light pollution. Now this season, at eight or nine o'clock in the evening, the Big Dipper will light up near the zenith again. Although you may not see the companion star in the city, the Big Dipper must be clearly visible. Of course, this also includes the giant star-Shu Tian.

If you don't understand, you can ask, hope to adopt, thank you!