Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Centaurus |
Right ascension | 13h 39m 53.25774s [1] |
Declination | −53° 27′ 59.0081″ [1] |
Apparent magnitude (V) | +2.30 [2] (2.29 - 2.31 [3]) |
Characteristics | |
Spectral type | B1 III [4] |
U−B color index | −0.92 [2] |
B−V color index | −0.22 [2] |
Variable type | β Cep [3] |
Astrometry | |
Radial velocity (Rv) | +3.0 [5] km/s |
Proper motion (μ) |
RA: −15.30
[1]
mas/
yr Dec.: −11.72 [1] mas/ yr |
Parallax (π) | 7.63 ± 0.48 mas [1] |
Distance | 430 ± 30
ly (131 ± 8 pc) |
Absolute magnitude (MV) | –3.9 [6] |
Details | |
Mass | 11.60 ± 1.06 [4] M☉ |
Luminosity | 15,217 [4] L☉ |
Surface gravity (log g) | 3.68 [6] cgs |
Temperature | 24,000 [4] K |
Metallicity [Fe/H] | –0.14 ± 0.10 [7] dex |
Rotational velocity (v sin i) | 160 [8] km/s |
Age | 15.8 ± 5.7 [9] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Epsilon Centauri (ε Cen, ε Centauri) is a star in the southern constellation of Centaurus. It is one of the brightest stars in the constellation with a slightly variable apparent visual magnitude of +2.30. Parallax measurements put it at a distance of around 430 light-years (130 parsecs) from Earth.
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 evolved giant 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 type variable 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–Centaurus OB 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]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Centaurus |
Right ascension | 13h 39m 53.25774s [1] |
Declination | −53° 27′ 59.0081″ [1] |
Apparent magnitude (V) | +2.30 [2] (2.29 - 2.31 [3]) |
Characteristics | |
Spectral type | B1 III [4] |
U−B color index | −0.92 [2] |
B−V color index | −0.22 [2] |
Variable type | β Cep [3] |
Astrometry | |
Radial velocity (Rv) | +3.0 [5] km/s |
Proper motion (μ) |
RA: −15.30
[1]
mas/
yr Dec.: −11.72 [1] mas/ yr |
Parallax (π) | 7.63 ± 0.48 mas [1] |
Distance | 430 ± 30
ly (131 ± 8 pc) |
Absolute magnitude (MV) | –3.9 [6] |
Details | |
Mass | 11.60 ± 1.06 [4] M☉ |
Luminosity | 15,217 [4] L☉ |
Surface gravity (log g) | 3.68 [6] cgs |
Temperature | 24,000 [4] K |
Metallicity [Fe/H] | –0.14 ± 0.10 [7] dex |
Rotational velocity (v sin i) | 160 [8] km/s |
Age | 15.8 ± 5.7 [9] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Epsilon Centauri (ε Cen, ε Centauri) is a star in the southern constellation of Centaurus. It is one of the brightest stars in the constellation with a slightly variable apparent visual magnitude of +2.30. Parallax measurements put it at a distance of around 430 light-years (130 parsecs) from Earth.
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 evolved giant 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 type variable 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–Centaurus OB 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]