Epsilon Centauri

In Chinese, 南門 (Nán Mén), meaning Southern Gate, refers to an asterism consisting of ε Centauri and α Centauri. Consequently, the Chinese name for ε Centauri itself is 南門一 (Nán Mén yī, English: the First Star of Southern Gate.)

ε Centauri is a massive star with 8.2 times the mass of the Sun. The spectrum matches a stellar classification of B1 III, indicating this is an evolved giant star. It is radiating more than 16,000 times the luminosity of the Sun from its outer atmosphere at an effective temperature of about 25,000 K, giving it the blue-white hue of a B-type star. It is classified as a Beta Cephei type variable star with a primary period of 0.16961 days (4 hours 4 minutes), completing 5.9 cycles per day. During each cycle, the brightness of the star varies from apparent magnitude +2.29 to +2.31.

This star is a proper motion member of the Lower Centaurus–Crux sub-group in the Scorpius–Centaurus OB association, the nearest such association of co-moving massive stars to the Sun. Epsilon Centauri is a relatively young star, with an age of around 16 million years.

The IAU has not assigned a proper name to this star.