The Chinese sky: Three Enclosures and 28 mansions

Its own way of joining the stars

Hundreds of small asterisms, many named after court life and everyday things.

The Hong Kong Space Museum (opens in a new tab) describes Chinese astronomy as having its own system for connecting the stars. The first Chinese star charts, by Shi Shen-fu, Gan De and Wu Xian, date from the Warring States period, about 400 BC, or earlier; later Chen Zhuo combined them into a catalogue of 283 asterisms and 1,464 stars.

Most of the 306 asterisms (opens in a new tab) the museum lists relate to the life of the imperial court and to everyday objects, which is why it describes the Chinese sky as a miniature of the earthly world.

The IAU (opens in a new tab) adds that many Chinese constellations have only one to three stars, gathered into super-constellations that divide the sky roughly into quarters.

Sources for this section Hong Kong Space Museum, Glossary of Chinese Star Regions, Asterisms and Star Names (opens in a new tab) · ; Hong Kong Space Museum, Chinese Starlore (opens in a new tab) · ; International Astronomical Union, The Constellations (opens in a new tab)

Three Enclosures and 28 mansions

Three walled regions around the pole, and 28 mansions along the Sun and Moon's path, in four Symbols.

In a poem written to help memorise the sky, Wang Xi-ming of the Tang dynasty divided it into 31 regions (opens in a new tab): the Three Enclosures, walled regions called the Purple Forbidden, the Supreme Palace and the Heavenly Market, and the Twenty-eight Mansions near the ecliptic and the Moon's path.

The mansions fall into four Symbols (opens in a new tab) of seven: the Azure Dragon in the east, the White Tiger in the west, the Vermilion Bird in the south and the Murky Warrior in the north. The museum compares the mansions to the twelve signs of the Western zodiac and notes that astronomers link their number to the Moon's 27⅓-day circuit of the sky.

The system kept growing: at the end of the Ming dynasty Xu Guang-qi (opens in a new tab) added 23 asterisms near the south pole from a Western catalogue, and Qing astronomers' revisions became the standard for traditional star maps.

Keep in mind These are Chinese regions with their own names, not Chinese nicknames for the 88 IAU constellations, and their boundaries do not match. The museum notes that scholars are still divided (opens in a new tab) on what some names mean.

Sources for this section Hong Kong Space Museum, Glossary of Chinese Star Regions, Asterisms and Star Names (opens in a new tab) · ; Hong Kong Space Museum, Chinese Starlore (opens in a new tab)

Some familiar stars, differently seen

The Big Dipper is the Northern Dipper; Antares is a heart; Canopus is the Old Man of longevity.

The seven stars of the Big Dipper are the Northern Dipper (opens in a new tab), each with its own name, from Celestial Pivot to Twinkling Brilliance, later worshipped as gods by Taoists; a saying holds that the Southern Dipper marks life and the Northern Dipper death.

Antares is the second star of Xin, the Heart mansion (opens in a new tab). The museum tells how Xin and the mansion Shen became two quarrelling brothers sent to opposite ends of the land, never to meet, as the two groups never share the sky.

Canopus is Laoren, the Old Man (opens in a new tab): so low on the southern horizon in China that it was seen only briefly, its appearance was taken to bring peace and prosperity, and it became the God of Longevity.

Sources for this section Hong Kong Space Museum, Chinese Starlore (opens in a new tab)

In the sky today

Every Chinese asterism is made of stars you can still find, inside the modern constellations.

The Northern Dipper is the Big Dipper; the Southern Dipper is in Sagittarius, where Ridpath (opens in a new tab) identifies it as the stars of today's Milk Dipper, part of the Teapot.

Shen and Xin are Orion and Scorpius, and Ridpath (opens in a new tab) notes that the two lie on opposite sides of the sky.

Sources for this section Ian Ridpath, Star Tales: Sagittarius (opens in a new tab) · ; Ian Ridpath, Star Tales: Scorpius (opens in a new tab)