HD 164427
HD 164427 is a star with a likely red dwarf companion in the southern constellation of Pavo. It has an apparent visual magnitude of 6.88, placing it just below the nominal limit for visibility with the typical naked eye. The annual parallax shift of 23.5 mas yields a distance estimate of 139 light-years (43 parsecs). It is moving further from the Earth with a heliocentric radial velocity of +3.4 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pavo |
| Right ascension | 18h 04m 42.58968s |
| Declination | −59° 12′ 34.4678″ |
| Apparent magnitude (V) | 6.88 |
| Characteristics | |
| Spectral type | G0+V |
| B−V color index | 0.624±0.015 |
| Astrometry | |
| Radial velocity (Rv) | +3.40±0.25 km/s |
| Proper motion (μ) | RA: −196.087 mas/yr Dec.: −51.219 mas/yr |
| Parallax (π) | 23.4516 ± 0.1836 mas |
| Distance | 139 ± 1 ly (42.6 ± 0.3 pc) |
| Absolute magnitude (MV) | 3.98±0.06 |
| Orbit | |
| Period (P) | 108.53855±0.00033 d |
| Semi-major axis (a) | 0.513+0.015 −0.016 AU |
| Eccentricity (e) | 0.54944±0.00073 |
| Inclination (i) | 9.340+0.066 −0.058° |
| Longitude of the node (Ω) | 337.69+0.41 −0.49° |
| Periastron epoch (T) | 2457368.358±0.017 |
| Argument of periastron (ω) (secondary) | −3.187+0.078 −0.070° |
| Semi-amplitude (K1) (primary) | 2.2162+0.0028 −0.0031 km/s |
| Details | |
| Mass | 1.19±0.14 M☉ |
| Radius | 1.404±0.037 R☉ |
| Luminosity | 2.66+0.48 −0.34 L☉ |
| Surface gravity (log g) | 4.216+0.062 −0.069 cgs |
| Temperature | 6,220+310 −240 K |
| Metallicity [Fe/H] | −0.06+0.22 −0.25 dex |
| Age | 6.6+1.3 −0.9 Gyr |
| HD 164427 B | |
| Mass | 0.339+0.002 −0.003 M☉ |
| Mass | 355.5+2.6 −2.9 MJup |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an inactive G-type main-sequence star given a stellar classification of G0+V by Gray et al. (2006), although Evans et al. (1964) classified it as a subgiant star with luminosity class IV. It is 6.6 billion years old with 1.125 times the mass of the Sun and 1.40 times the Sun's radius. The star is somewhat over-luminous for its class, radiating 2.33 times the Sun's luminosity from its photosphere at an effective temperature of 5,876 K.