Kappa Boötis


Kappa Boötis is a double star in the constellation Boötes. It has the traditional name Asellus Tertius and the Flamsteed designation 17 Boötis. The components are separated by an angular distance of 13.5 arcsec, viewable in a small telescope. Kappa Boötis is approximately 155 light years from Earth.

Nomenclature

This star, along with the other Aselli and λ Boo, were Aulād al Dhiʼbah, "the Whelps of the Hyenas".
In Chinese, 天槍, meaning Celestial Spear, refers to an asterism consisting of κ Boötis, ι Boötis and θ Boötis. Consequently, the Chinese name for κ Boötis itself is 天槍一

Properties

κ1 Boötis is a spectroscopic binary star system. The visible primary is an F2 main sequence star, while the secondary is half the mass and much fainter.
κ2 Boötis is classified as a Delta Scuti type variable star with a period of 1.08 hours Its brightness varies from magnitude +4.50 to +4.58. It is a slightly evolved A8 subgiant.