Theta Centauri
Observation data Epoch J2000.0 Equinox J2000.0 |
|
---|---|
Constellation | Centaurus |
Right ascension | 14h 06m 40.94752s[1] |
Declination | –36° 22′ 11.8371″[1] |
Apparent magnitude (V) | +2.06[2] |
Characteristics | |
Spectral type | K0 III[3] |
U−B color index | +0.90[2] |
B−V color index | +0.99[2] |
Astrometry | |
Radial velocity (Rv) | +1.3[4] km/s |
Proper motion (μ) | RA: –520.53[1] mas/yr Dec.: –518.06[1] mas/yr |
Parallax (π) | 55.45 ± 0.20[1] mas |
Distance | 58.8 ± 0.2 ly (18.03 ± 0.07 pc) |
Absolute magnitude (MV) | 0.87[5] |
Details | |
Radius | 10.6[6] R☉ |
Luminosity | 60[7] L☉ |
Surface gravity (log g) | 2.75[8] cgs |
Temperature | 4,980[8] K |
Metallicity [Fe/H] | 0.03[8] dex |
Other designations | |
Theta Centauri (θ Cen, θ Centauri) is a star in the southern constellation of Centaurus, the centaur. It has the traditional Arabic name Menkent (possibly abbreviation of ألمنكب ألقنتوس - al mankib al-qanturis, meaning "shoulder of the Centaur"). This star has an apparent visual magnitude of +2.06,[2] making it the fourth brightest member of the constellation. This star is close enough to the Earth that its distance can be measured using the parallax technique, yielding a value of 58.8 light-years (18.0 parsecs).[1]
In Chinese, 庫樓 (Kù Lóu), meaning Arsenal, refers to an asterism consisting of θ Centauri, ζ Centauri, η Centauri, 2 Centauri, HD 117440, ξ1 Centauri, γ Centauri, τ Centauri, D Centauri and σ Centauri.[10] Consequently, θ Centauri itself is known as 庫樓三 (Kù Lóu sān, English: the Third Star of Arsenal.)[11]
This is an evolved giant star with a stellar classification of K0 III.[3] The interferometry-measured angular diameter of this star, after correcting for limb darkening, is 5.46 ± 0.06 mas,[12] which, at its estimated distance, equates to a physical radius of about 10.6 times the radius of the Sun.[6] The outer envelope has an effective temperature of 4,980 K,[8] giving it the orange-hued glow of a cool, K-type star.[13] Soft X-ray emission has been detected from this star, which has an estimated X-ray luminosity of 1.4 × 1027 erg s−1.[14]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found.. The radius (R*) is given by:
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 8.0 8.1 8.2 8.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ (Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ↑ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.