Chinese constellations

Lore & Background

The Chinese system of asterisms developed independently from the Greco-Roman system since at least the 5th century BC, though parallels to ancient Babylonian astronomy suggest possible earlier mutual influence. The system of twenty-eight lunar mansions is very similar to the Indian Nakshatra system, but it is not known if there was mutual influence. The oldest extant Chinese star maps date to the Tang dynasty, including the 8th-century Treatise on Astrology of the Kaiyuan Era and the Dunhuang Star Chart, which contains collections from earlier Chinese astronomers such as Shi Shen, Gan De, and Wu Xian, as well as Indian astronomy that reached China in the early centuries AD. The number of asterisms and stars never became fixed; for example, the 13th-century Suzhou planisphere shows 283 asterisms with 1,565 stars, while the 14th-century Korean Cheonsang Yeolcha Bunyajido has 264 asterisms with 1,467 stars.

Reader's Guide

The Chinese asterisms are divided into four groups: the Twenty-Eight Mansions along the ecliptic and the Three Enclosures of the northern sky. The Twenty-Eight Mansions form an ecliptic coordinate system based on the Moon's movement over a lunar month, used for stars not visible year-round from China. The Three Enclosures include the Purple Forbidden Enclosure, centered on the north celestial pole and containing stars visible year-round, while the other two straddle the celestial equator. The southern sky was unknown to ancient Chinese and was added as a fifth group in the late Ming dynasty, based on European star charts, comprising 23 additional asterisms. Chinese star names are systematically assigned by asterism and number, predating Johann Bayer's similar method by over a thousand years. These designations are still used in modern Chinese astronomy, and stars with traditional names in English are routinely translated from their Chinese designations.

Did You Know?

• The Chinese word for 'constellation' in the traditional system is 星官 (xīng guān), meaning 'officials'.
• The Dunhuang Star Chart has 1,585 stars grouped into 257 asterisms.
• The Purple Forbidden Enclosure covers Greek constellations including Ursa Minor, Draco, and Cassiopeia.
• Altair is named 河鼓二 in Chinese, meaning 'the Second Star of the Drum at the River'.