HD 170469
HD 170469 is a probable binary star system in the equatorial constellation of Ophiuchus. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.21. The system is located at a distance of 197 light years away from the Sun based on parallax. It is drifting closer with a radial velocity of −59 km/s, and is expected to come to within 49.8 light-years in about 959,000 years.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 18h 29m 10.98124s |
| Declination | +11° 41′ 43.7985″ |
| Apparent magnitude (V) | 8.21 |
| Characteristics | |
| Spectral type | G5V + K5V |
| B−V color index | 0.677±0.014 |
| Astrometry | |
| Radial velocity (Rv) | −59.32±0.10 km/s |
| Proper motion (μ) | RA: −48.418±0.070 mas/yr Dec.: −17.470±0.079 mas/yr |
| Parallax (π) | 16.5886 ± 0.0408 mas |
| Distance | 196.6 ± 0.5 ly (60.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.23 |
| Orbit | |
| Primary | HD 170469 |
| Companion | HD 170469 B |
| Period (P) | 114000 yr |
| Semi-major axis (a) | 43.1″ |
| Details | |
| A | |
| Mass | 1.10 M☉ |
| Radius | 1.24 R☉ |
| Luminosity | 1.639±0.006 L☉ |
| Surface gravity (log g) | 4.30±0.03 cgs |
| Temperature | 5,786±28 K |
| Metallicity [Fe/H] | 0.28±0.02 dex |
| Age | 4.8+3.0 −0.5 or 8.6±0.5 Gyr |
| B | |
| Mass | 0.42 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary, component A, is a G-type main-sequence star with a stellar classification of G5V, indicating it is generating energy through core hydrogen fusion. Estimates of the star's age range from five to almost nine billion years. It has 1.10 times the mass of the Sun and 1.24 times the Sun's radius. The star has a higher than solar metallicity. It is radiating 1.64 times the Sun's luminosity from its photosphere at an effective temperature of 5,786 K.
The secondary companion, component B, is located at an angular separation of 43.21″±0.10″ along a position angle of 112.55°±0.07° from the primary, as of 2018. Initially it was thought to be a red dwarf of spectral class M1, but was later determined to be a K-type main-sequence star with a class of K5V. This star lies at a projected separation of 2708 AU from the primary, and is orbiting with an estimated period of around 114,000 years.