Theta Arae
Theta Arae is a star in the southern constellation Ara. Its name is a Bayer designation that is Latinized from θ Arae, and abbreviated Theta Ara or θ Ara. This star 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. At an age of 28 million years, it has a high rate of spin with a projected rotational velocity of 95 km/s. This star has nearly nine times the mass of the Sun and 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.