The Chinese system developed independently from the Greco-Roman system since at least the 5th century BC, although there may have been earlier mutual influence, suggested by parallels to ancient
Babylonian astronomy. The system of twenty-eight lunar mansions is very similar (although not identical) to the
Indian Nakshatra system, and it is not currently known if there was mutual influence in the history of the Chinese and Indian systems. The oldest extant
Chinese star maps date to the
Tang dynasty. Notable among them are the 8th-century
Treatise on Astrology of the Kaiyuan Era and
Dunhuang Star Chart. It contains collections of earlier Chinese astronomers (
Shi Shen,
Gan De and
Wu Xian) as well as of
Indian astronomy (which had reached China in the
early centuries AD). Gan De was a
Warring States era (5th century BC) astronomer who according to the testimony of the Dunhuang Star Chart enumerated 810 stars in 138 asterisms. The Dunhuang Star Chart itself has 1,585 stars grouped into 257 asterisms. The number of asterisms, or of stars grouped into asterisms, never became fixed, but remained in the same order of magnitude (for the purpose of comparison, the star catalogue compiled by
Ptolemy in the 2nd century had 1,022 stars in 48 constellations). The 13th-century Suzhou star chart has 1,565 stars in 283 asterisms, the 14th-century Korean
Cheonsang Yeolcha Bunyajido has 1,467 stars in 264 asterisms, and the celestial globe made by Flemish Jesuit
Ferdinand Verbiest for the
Kangxi Emperor in 1673 has 1,876 stars in 282 asterisms. The southern sky was unknown to the ancient Chinese and is consequently not included in the traditional system. With
European contact in the 16th century,
Xu Guangqi, an astronomer of the late
Ming dynasty, introduced another 23 asterisms based on European star charts. The "Southern Asterisms" () are now also treated as part of the traditional Chinese system. ==Terminology==