Rho Boötis

Rho Boötis (ρ Boo, ρ Boötis) is a star in the northern constellation Boötes. Based upon parallax measurements, it is located at a distance of approximately 149 light-years (46 parsecs) from Earth.

This is an orange K-type giant with an apparent magnitude of +3.57. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. There is an optical companion, an eleventh magnitude star, located 42 arcseconds away.

In Chinese, 梗河 (Gěng Hé), meaning Celestial Lance, refers to an asterism consisting of ρ Boötis, ε Boötis and σ Boötis. Consequently, ρ Boötis itself is known as 梗河三 (Gěng Hé sān, English: the Third Star of Celestial Lance.)