12 Aquilae
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 01m 40.82707s[1] |
| Declination | –05° 44′ 20.8134″[1] |
| Apparent magnitude (V) | 4.02[2] |
| Characteristics | |
| Spectral type | K1 III[3] |
| U−B color index | +1.04[2] |
| B−V color index | +1.104[4] |
| R−I color index | 0.54 |
| Astrometry | |
| Radial velocity (Rv) | –43.92 ± 0.18[4] km/s |
| Proper motion (μ) | RA: –24.41[1] mas/yr Dec.: –39.66[1] mas/yr |
| Parallax (π) | 22.66 ± 0.23[1] mas |
| Distance | 144 ± 1 ly (44.1 ± 0.4 pc) |
| Absolute magnitude (MV) | 0.726[5] |
| Details | |
| Radius | 12[4] R☉ |
| Luminosity | 60[4] L☉ |
| Surface gravity (log g) | 2.6[4] cgs |
| Temperature | 4,603[4] K |
| Metallicity [Fe/H] | –0.19[5] dex |
| Rotational velocity (v sin i) | 3.6[4] km/s |
| Age | 4.64 ± 2.35[5] Gyr |
| Other designations | |
12 Aquilae (abbreviated 12 Aql) is a star in the equatorial constellation of Aquila. 12 Aquilae is the Flamsteed designation though it also bears the Bayer designation i Aquilae. Sometimes, this star is called by the name Bered, derived the Hebrew word בָּרָד barad, meaning "storm". In Chinese, 天弁 (Tiān Biàn), meaning Market Officer, refers to an asterism consisting of 12 Aquilae, α Scuti, δ Scuti, ε Scuti, β Scuti, η Scuti, λ Aquilae, 15 Aquilae and 14 Aquilae.[7] Consequently, 12 Aquilae itself is known as 天弁六 (Tiān Biàn liù, English: the Sixth Star of Market Officer.)
This star has an apparent visual magnitude of 4.02,[2] which is bright enough to be seen with the naked eye, although, according to the Bortle Dark-Sky Scale, it is a challenge to view from the inner city. Based upon an annual parallax shift of 22.66 mas, the distance to this star is 144 light-years (44 parsecs) with a margin of error of one light-year. This is an evolved giant star of stellar class K1 III.[3] It has 12[4] times the radius of the Sun and shines with 60[4] times the Sun's luminosity. This energy is being radiated from its outer atmosphere at an effective temperature of 4,603 K,[4] giving it the cool orange hue of a K-type star.[8]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 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.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 5.2 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.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
