Theta Arae

Theta Arae (θ Ara, θ Arae) is the Bayer designation for a star in the constellation Ara. It has an apparent visual magnitude of +3.67, which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 4.01 mas, Theta Arae is 810 light-years (250 parsecs) distant from the Earth.

This is a supergiant star with a stellar classification of B2 Ib. It has nearly nine times the mass of the Sun and is over 20 times the Sun's radius. The outer atmosphere of this star has an effective temperature of 17,231 K; much hotter than the surface of the Sun. At this heat, the star shines with the characteristic blue-white hue of a B-type star.