39 Boötis is a triple star system located around 224 light years away from the Sun in the northern constellation of Boötes. It is visible to the naked eye as a faint, yellow-white hued star with a combined apparent magnitude of 5.68. The system is moving closer to the Earth with a heliocentric radial velocity of −31 km/s.
The magnitude 6.36 primary, component A, is actually a double-lined spectroscopic binary system with an orbital period of 12.822 days, an eccentricity of 0.39, and an angular separation of . It has a combined stellar classification of F8V, matching an F-type main-sequence star, with individual massed of 1.29 and 1.05 times the mass of the Sun. Component B is of magnitude 6.72 with a class of F7V and 1.25 solar masses. The A–B pair have a separation of and a period of 1,347.653 years. This system is a source of X-ray emission with a luminosity of .
It was a transferred by Jérôme Lalande from Boötes to Quadrans Muralis. Later when the International Astronomical Union officially recognised constellations, Quadrans Muralis became obsolete, so this star was moved back to Boötes. References