What was the "guest star" that appeared at the end of the Eastern Han Dynasty?

This is the ancient astrological saying that "the guest star invaded Wei Zi". Wei Zixing refers to the emperor, and then it is said that the guest star is the main battle.

China's ancient collective name for the new stars in the sky. It mainly refers to nova, supernova and comet, and occasionally includes astronomical phenomena such as meteor and aurora. Such celestial bodies, like "guests", are located among the common stars in the sky, so they are called guest stars. In ancient astrology in China, guest stars are often divided into two categories: nova and demon stars. The former indicates good luck, while the latter indicates all kinds of bad luck.

Records about guest stars.

The name "guest star" was first seen in the Han Dynasty. For example, it is recorded in Hanshu Tian that "in May of the first year of Yuanguang, the guest star was seen in the house." This is a new star that appeared in 134 BC.

Supernovae that appeared near Guanxing Star in Taurus in the Song Dynasty and the first year (AD 1054) should be the most famous records about the guest star. This supernova took two years to darken. "Song Yao Hui" records: "In March of the first year, Si Tian predicted that there would be no guest stars, and the guests would go. From the beginning to the fifth month of the first year, I went out to the east in the morning and closed the sky. I will see it is white during the day, the corners are red and white, and I will see it on the 23rd. " At the end of 18, someone observed a crab-like nebula with a telescope and named it the crab nebula. In 192 1, it is found that this crab nebula is expanding outward. According to the calculation of expansion speed, this nebula material flew out of a center about 900 years ago, which is very consistent with the time recorded in Song Dynasty and its position is similar. Many astronomers have proved that the Crab Nebula is the remnant of 1054 Taurus supernova.