Bodu (帛度)
Bó Dù (帛度, “Textile Ruler”) is a Chinese asterism consisting of two stars, established by the Wuxian (巫咸) tradition during the Han dynasty. Together with Tusi (屠肆), the Butcher Shop, it formed a double-asterism within the Chinese super-constellation of Tianshi (天市), the Celestial Market Place. Since 2025, "Bodu" is also the IAU-star name of 95 Her, a white subgiant in the constellation of Hercules.
Etymology and History
The term bo (帛) refers broadly to silk fabrics, while du (度) denotes either units or instruments of length measurement. Thus, Bodu could be interpreted as a tool used for measuring textiles, or by extension, as a shop engaged in the sale of such goods. The Han dynasty (202 BCE - 220 CE) classic Liji (礼记, Book of Rites) contains strict specifications for commodities, including textiles. It states: “Cloth and silk that are either too fine or too coarse to meet the standard, or whose widths are not properly measured, shall not be permitted in the market.” According to Han regulations, government-issued cloth was required to be “2 chi and 2 cun in width” (1 chi is about 23.1-24.3 cm in Han, 1 cun is 0.1 chi). The establishment of this asterism may have been informed by such institutional frameworks regulating textile production and trade.
Astrologers later generalized the meaning of Bodu to represent all measurement, commercial standardization, and market regulation. Since textile trade was primarily associated with women, some traditions even employed this asterism to divine matters related to women’s purchases in the marketplace.
Identification of stars
Some star charts depict Bodu as oriented east–west, while others depict it in a north–south arrangement. It is located near the Tusi (屠肆) (Butcher’s Shop) asterism, and several charts depict the two together as forming a connected rectangular shape. Given their small size and the low precision of ancient mapping techniques, slight variations in their relative positions are frequent. Interestingly, while the position of Tusi often varies across ancient catalogues, Bodu remains remarkably stable—aside from a few erroneous identifications of the coordinate in Huangyou Star Catalogue (皇祐星表) by modern scholars, the coordinates in various catalogues points to 95 Her and 102 Her. For visual representations of Bodu, see the entry Tusi (屠肆).
| Star Names or Orders(Traditional/Qing) | Yi Shitong[1]
Based on catalogue in 18th century |
Pan Nai[2]
based on Huangyou Star Catalogue |
Pan Nai[3]
based on catalogues in Yuan dynasty |
SUN X. & J. Kistemaker[4]
Han Dynasty |
Boshun Yang[5]
before Tang dynasty |
Boshun Yang[5]
Song Jingyou(1034) |
Boshun Yang[5]
Song Huangyou(1052) |
|---|---|---|---|---|---|---|---|
| 1st/Determinative | 95 Her | 96 Her | 96 Her | 96 Her | 102 Her | 95 Her | 95 Her |
| 2nd | 102 Her | 101 Her | 101 Her | 101 Her | 95 Her | 102 Her | 102 Her |
Maps (Gallery) source
| historical map | modern identification
(Yang 2023) |
same in Stellarium 25.1 |
|---|---|---|
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Star Name Discussion (IAU)
In 2025, the name of the historical constellation "Bodu" was suggested to be used for one of the stars in this constellation. In June 2025, WGSN chose to adopt the name according to the Yi Shitong catalog because earlier identifications are highly uncertain.
Bodu is now the IAU-name for the star 95 Her, a hot white subgiant of 2.8 solar masses at a distance of 432 light years.
References
- ↑ Yi Shitong伊世同. Zhongxi Duizhao Hengxing Tubiao中西对照恒星图表1950. Beijing: Science Press.1981: 32.
- ↑ Pan Nai潘鼐. Zhongguo Hengxing Guance shi中国恒星观测史[M]. Shanghai: Xuelin Pree. 2009. p305.
- ↑ Pan Nai潘鼐. Zhongguo Hengxing Guance shi中国恒星观测史[M]. Shanghai: Xuelin Pree. 2009. p438.
- ↑ Sun Xiaochun. & Kistemaker J. The Chinese sky during the Han. Leiden: Brill. 1997, Pp241-6.
- ↑ 5.0 5.1 5.2 B.-S. Yang杨伯顺, Zhongguo Chuantong Hengxing Guance Jingdu ji Xingguan Yanbian Yanjiu 中国传统恒星观测精度及星官演变研究 (A Research on the Accuracy of Chinese Traditional Star Observation and the Evolution of Constellations), PhD thesis, (Hefei: University of Science and Technology of China, 2023). 248.
