Kappa Aquilae
 Location of κ Aquilae (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 36m 53.44952s[1] |
| Declination | –7° 01′ 38.9176″[1] |
| Apparent magnitude (V) | +4.957[2] |
| Characteristics | |
| Spectral type | B0.5 III[3] |
| U−B color index | –0.861[2] |
| B−V color index | –0.028[2] |
| Astrometry | |
| Radial velocity (Rv) | –19.4[4] km/s |
| Proper motion (μ) | RA: +1.63[1] mas/yr Dec.: –2.65[1] mas/yr |
| Parallax (π) | 1.94 ± 0.20[1] mas |
| Distance | approx. 1,700 ly (approx. 520 pc) |
| Details | |
| Mass | 15.50 ± 0.61[5] M☉ |
| Radius | 12.5[6] R☉ |
| Luminosity | 52,630[5] L☉ |
| Surface gravity (log g) | 3.5[7] cgs |
| Temperature | 26,500[5] K |
| Rotational velocity (v sin i) | 265[8] km/s |
| Age | 11.1 ± 0.5[3] Myr |
| Other designations | |
Kappa Aquilae (κ Aql, κ Aquilae) is the Bayer designation for a star in the equatorial constellation of Aquila. It is a faint star at apparent visual magnitude +4.957,[2] but bright enough to be seen with the naked eye in dark suburban skies. The annual parallax is only 1.94 mas,[1] which equates to a distance of approximately 1,700 light-years (520 parsecs) from Earth (with a 10% margin of error).
The spectrum of Kappa Aquilae matches a stellar classification of B0.5 III,[3] where the luminosity class of III is typically associated with evolved giant stars. This is a huge star with 15.50[5] times the Sun's mass and 12.5[6] times the radius of the Sun. Massive stars like this blaze brightly; it is radiating 52,630-fold[5] the Sun's luminosity from its outer atmosphere with a scorching effective temperature of 26,500 K,[5] giving it the intense blue-white glow of a B-type star. It is only 11 million years of age[3] and is spinning rapidly with a projected rotational velocity of 265 km/s.[8]
References
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- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 3.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 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.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 8.0 8.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
