26 Aquilae
 Location of 26 Aquarii (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 20m 32.90437s[1] |
| Declination | –05° 24′ 56.7440″[1] |
| Apparent magnitude (V) | 5.00[2] |
| Characteristics | |
| Spectral type | G8 III-IV[3] |
| U−B color index | +0.634[2] |
| B−V color index | +0.936[2] |
| R−I color index | 0.5 |
| Astrometry | |
| Radial velocity (Rv) | −16.91±1.93[4] km/s |
| Proper motion (μ) | RA: +113.13[1] mas/yr Dec.: +46.20 [1] mas/yr |
| Parallax (π) | 21.15 ± 0.39[1] mas |
| Distance | 154 ± 3 ly (47.3 ± 0.9 pc) |
| Orbit[4] | |
| Period (P) | 266.544 days |
| Eccentricity (e) | 0.833 |
| Semi-amplitude (K1) (primary) |
29.86 km/s |
| Details | |
| 26 Aquilae A | |
| Mass | 3.2+0.2 −0.2[5] M☉ |
| Radius | 6[4] R☉ |
| Luminosity | 21[4] L☉ |
| Surface gravity (log g) | 3.2[4] cgs |
| Temperature | 4940[5] K |
| Metallicity [Fe/H] | –0.21[4] dex |
| Rotational velocity (v sin i) | 1.3[4] km/s |
| 26 Aquilae B | |
| Mass | 1.4±0.05[5] M☉ |
| Other designations | |
26 Aquilae (abbreviated 26 Aql) is a binary star system in the equatorial constellation of Aquila. 20 Aquilae is its Flamsteed designation though it also bears the Bayer designation f Aquilae. It has an apparent visual magnitude of 5.00,[2] which means it is faintly visible to the naked eye. As the Earth orbits the Sun, this star system undergoes a parallax shift of 21.15 mas.[1] This means it is located at a distance of approximately 154 light-years (47 parsecs) from Earth, give or take a 3 light-year margin of error.
This is a single-lined spectroscopic binary system, meaning that the presence of an orbiting companion is revealed through shifts in the spectrum of the primary star. The pair orbit each other with a period of 266.544 days at a high eccentricity of 0.833.[4] Little is known about this companion, although its mass can be estimated as 140% of the mass of the Sun.
The primary component has a stellar classification of G8 III-IV.[3] The luminosity class of III-IV indicates the spectrum resembles that of a star part way between the subgiant and giant stages of its evolution. It has more than three[5] times the mass of the Sun and six[4] times the Sun's radius. It is radiating 21[4] times as much luminosity as the Sun from this enlarged outer envelope at an effective temperature of 4940 K.[5] At this heat, the star glows with the characteristic yellow hue of a G-type star.[7]
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.
- ↑ 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 5.3 5.4 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.
