binary star
Astronomical term for a system of two stars orbiting each other. Synonymous with 連星 (れんせい).
See also: 連星
シリウスは双子星の一つです。
Sirius is one of the binary stars.
この望遠鏡で双子星を観測できる。
You can observe binary stars with this telescope.
Compound of 双子 (ふたご, 'twins') and 星 (ほし, 'star'), literally 'twin stars'. The reading ほし becomes ぼし due to rendaku.