Monday, May 20, 2013

Research and resources on Chinese astronomy

The Chinese Sky. Poster available from IDP (see below).
Illustrations by Nilesh Mistry.

The world's oldest existing manuscript star chart was discovered in a Buddhist cave complex in Dunhuang, China, and is now held at the British Library in London. The chart is important for our current understanding of the history of astronomy, thanks to the accuracy and detail it provides about the sky seen from China at this early period. Research by French scholars working with IDP has shown that the chart, sometimes referred to as the Dunhuang Star Chart, maps over 1300 stars and probably dates from about AD 650.

Astronomy was central to Chinese politics, to the extent that all the official dynastic historical records contain chapters on astronomy. Chinese astronomy differs from the ecliptic-based Chaldeo-Greek tradition in its equatorial character, due to the central role of the polar star. The celestial region close to the equator is divided in 28 asterisms (groups of stars), which can be considered as an equatorial Chinese zodiac. The grouping of the stars in China is also totally different from the Greek tradition of large constellations. The Chinese grouped the stars into numerous small asterisms (nearly three hundred), some associated with objects and others with people, both real and mythical. Many stories became associated with these characters.

IDP has a downloadable educational resource on Chinese astronomy and astrology. Comprising information pages, discussion topics and classroom activities, it uses the Dunhuang Star Chart as the basis for an exploration into the science, myth and history of Chinese astronomy. The resources includes an A4 version of the Chinese Sky wall chart (pictured above) which you can download as a PDF (7.9MB) and print yourself. Copies of the A1 wall chart are also available to teachers and students through IDP.

For your free copy of the A1 size chart, please email with an address for postage. Contributions towards postage and packing will be gratefully received. We welcome feedback, so if you have any comments or pictures relating to your experience of using these resources, please get in touch.

The research and resource were enabled by a grant from the Royal Astronomical Society.


  1. A friend mentioned that for a correct depiction of the four animals with the four seasons the tortoise and the bird should swap places. I think he is correct, if you want to put South on top, which was the custom in ancient China. If you want to keep North on top you should swap the tiger and the dragon.

    1. This is the same configuration as the more famous Suzhou planisphere of 1193 (See Needham, SSIC, III:280). The key is understanding the star chart as a view of the heavens theoretically available to a person standing on the north pole looking up. On Han dynasty astrological instruments such as the cosmograph (shipan), which depict the heavens from the point of view of Shangdi (the Lord on High) on his throne in Beidou (the Big Dipper) looking down on the earth, the position of the dragon and tiger are indeed reversed. In the IDP illustration, the four animals do correspond to their constituent constellations. For example, the dragon's mouth partially covers the tail of Scorpio (the tail of Canglong in the Chinese sky), while the tiger's head lies just below Orion (the head and forelegs of Baihu).

  2. Thank you for your explanation, Stephen. I never considered the point of view of the observer, but actually it is quite logical. Confusing, but logical :-) .