Beta Arae

Beta Arae (β Ara, β Arae), is the brightest star in the constellation of Ara. It is a very luminous, relatively young, giant or supergiant star with an apparent magnitude of 2.84 and an absolute magnitude of -3.494. It is located about 713 light-years from Earth. At this distance, its apparent magnitude is diminished by 0.193 magnitudes due to interstellar extinction between Earth and the star.

Characteristics
The spectrum of this star matches a stellar classification of K3 Ib-IIa, with the luminosity class notation 'Ib-IIa' indicating that the star lies part way between a higher luminosity bright giant (IIa) and a lower luminosity supergiant (Ib). It has an age estimated at 50 million years, having spent much of its life as a B-type star. Currently, it has expanded to 141 times the Sun's size and is 5,800 times more energetic. Beta Arae is radiating energy from its outer envelope at an effective temperature of $-0.3$, which causes it to take on the orange hue of a K-type star. This enlarged star appears to be rotating slowly with a projected rotational velocity of about $218.8$. The abundance of elements other than hydrogen and helium, its metallicity, is more than three times that of the Sun.

Nomenclature
Beta Arae is the star's Bayer designation. Other designations include HD 157244 (from the Henry Draper Catalogue), HIP 85258 (from the Hipparcos catalogue) and HR 6461 (from the Bright Star Catalogue).

Rarely, this star is called Vasat-ül-cemre a Turkisation of Arabic وسط الجمر (wasaṭ al-jamar), meaning "middle of the embers." The constellation is named in Arabic المجمرة (al-mijmarah), meaning brazier/incense-burner. In Chinese, 杵 (Chǔ), meaning Pestle, refers to an asterism of β, σ and α Arae. The Chinese name for β Arae is 杵三 (Chǔ sān, the Third Star of Pestle.)