While Western astronomers of the Renaissance period were still arguing in 1615 who was the first to discover sunspots, Chinese astronomers had already accumulated a large amount of records on sunspots. Now it is known that the earliest record on sunspots was made in 28 BC by ancient Chinese astronomers during the reign of Emperor Cheng of the Western Han Dynasty.

By the late Ming Dynasty in the mid-17th century, more than 100 sunspots had been recorded in Chinese historic books. Moreover, they also took note of other phenomena concerning the sun, such as solar prominences and coronas. The first record of a solar prominence has been found in a tortoise shell inscription, which describes "three suddenly bursting fires eating a chunk of the sun". According to statistics, sunspots occur in a cycle every 11.33 years on average, which is in conformity with ancient Chinese documents and once again testifies to the fact that records of sunspots made by ancient Chinese people are a very valuable astronomical legacy.

Author: Jessie