In
Chinese, 南門 (Nán Mén), meaning Southern Gate, refers to an asterism consisting of ε Centauri and
α Centauri.[10] Consequently, the
Chinese name for ε Centauri itself is 南門一 (Nán Mén yī, English: the First Star of Southern Gate.)[11]
ε Centauri is a massive star with nearly 12 times the mass of the Sun.[4] The
spectrum matches a
stellar classification of B1 III,[4] indicating this is an
evolvedgiant star. It is radiating more than 15,000[4] times the luminosity of the Sun from its outer atmosphere at an
effective temperature of 24,000 K,[4] giving it the blue-white hue of a B-type star.[13] This is classified as a
Beta Cephei typevariable star with a primary period of 0.16961 days (4 hours 4 minutes), completing 5.9 cycles per day.[7] 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–CentaurusOB association, the nearest such association of co-moving massive stars to the Sun.[6] Epsilon Centauri is a relatively young star, with an age of around 16 million years.[9]
The
IAU has not assigned a proper name to this star.[14]
^
abcDucati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0.
Bibcode:
2002yCat.2237....0D.
^
abSamus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: 02025.
Bibcode:
2009yCat....102025S.
^Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto:
International Astronomical Union, p. 57,
Bibcode:
1967IAUS...30...57E
^
abcde Geus, E. J.; de Zeeuw, P. T.; Lub, J. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", Astronomy and Astrophysics, 216 (1–2): 44–61,
Bibcode:
1989A&A...216...44D