Zeta Boötis


Zeta Boötis, Latinized as ζ Boötis, is a binary star system in the constellation of Boötes that consists of two giant stars with matching stellar classifications of A2III. They have the Flamsteed designation 30 Boötis. This system is approximately 180 light years from Earth and has a combined apparent magnitude of +3.78. The individual magnitudes differ slightly, with component A having a magnitude of 4.43 and component B at the slightly dimmer magnitude 4.83.
The binary nature of this system has been tracked since 1796. They complete an orbit roughly every 45,460 days, or 124.46 years. The next close approach will occur during August 2023. The orbit of this pair has a very high eccentricity of 0.9977, bringing the stars within 0.3 AU at their closest approach.