Delta Boötis
Delta Boötis, Latinized from δ Boötis, is a double star in the northern constellation of Boötes, forming the easternmost member of the constellation's kite-shaped asterism of brighter stars. Based upon parallax measurements, it is located at a distance of approximately from the Earth. This star is sometimes called Princeps , meaning prince or prime in Latin. The origin of this name is unclear, although it usually appears in an astrological context. The apparent visual magnitude of this star is 3.5, making it visible to the naked eye even during a Full Moon. The magnitude 7.81 companion can be viewed in binoculars or a small telescope. In Chinese, (), meaning Seven Excellencies, refers to an asterism consisting of δ Boötis, 42 Herculis, τ Herculis, φ Herculis, χ Herculis, ν1 Boötis and μ1 Boötis. Consequently, the Chinese name for δ Boötis itself is (, .) Properties This system consists of a pair of stars located in physical proximity to each other and sharing a similar motion through space, suggesting that they may form a binary star system. Based upon their angular separation and their distance, they have a projected separation of 3,800 Astronomical Units (AU). However, their separation along the line of