Tianyi
Designations
- Flamsteed: 7 Dra
- Hipparchos: HIP 62423
Data
- Constellation: Draco
- Apparent Magnitude: 5.42
- Right Ascension (J2000): 12h47m33.18s
- Declination (J2000): +66°47'43".6
- Colour Index (B-V): 1.58
- Distance: 722.88±9.16ly
Nomenclature
Tianyi
The name is from Chinese 天一 Tiānyī, 'Heavenly Unity'. It was originally equated with 太一 Tàiyī, 'August Unity, or Supreme One', and as such comprised a single-star asterism just outside the 紫微右垣 Zǐwēiyòuyuán, 'Purple Palace Right Wall'. It was during the Han period that the two figures were differentiated. Taoist scholars such as Miu Ju, in pursuit of the ultimate 道 dào, suggested to Emperor Wu of Han that Tàiyī was the more supreme star (for more on the history of the Supreme One, see Taiyi (8 Dra)). As a separate asterism, Tiānyī represented the 阴 yīn and 阳 yáng that Tàiyī governed.
Sources
- IAU WGSN. IAU-Catalog of Star Names (CSN). link.
- Stellarium Contributors. Stellarium Astronomy Software. link.
- Rufus, W. Carl. Hsing-chih T'ien. The Soochow Astronomical Chart (), pp. 15. link.
- Xiaochun, S., Kistemaker, J. The Chinese sky during the Han : constellating stars and society (), pp. 50, 84-85, 166-167.