HD 170469
Star in the constellation Ophiuchus
From Wikipedia, the free encyclopedia
HD 170469 is a probable binary star[7][4] 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.[2] 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,[3] 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[1] |
| Declination | +11° 41′ 43.7985″[1] |
| Apparent magnitude (V) | 8.21[2] |
| Characteristics | |
| Spectral type | G5V + K5V[3] |
| B−V color index | 0.677±0.014[2] |
| Astrometry | |
| Radial velocity (Rv) | −59.32±0.10[3] km/s |
| Proper motion (μ) | RA: −48.418±0.070[1] mas/yr Dec.: −17.470±0.079[1] mas/yr |
| Parallax (π) | 16.5886±0.0408 mas[1] |
| Distance | 196.6 ± 0.5 ly (60.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.23[2] |
| Orbit[4] | |
| Primary | HD 170469 |
| Name | HD 170469 B |
| Period (P) | 114000 yr |
| Semi-major axis (a) | 43.1″ |
| Details | |
| A | |
| Mass | 1.10[5] M☉ |
| Radius | 1.24[5] R☉ |
| Luminosity | 1.639±0.006[1] L☉ |
| Surface gravity (log g) | 4.30±0.03[5] cgs |
| Temperature | 5,786±28[3] K |
| Metallicity [Fe/H] | 0.28±0.02[3] dex |
| Age | 4.8+3.0 −0.5[2] or 8.6±0.5[6] Gyr |
| B | |
| Mass | 0.42[7] M☉ |
| Other designations | |
| t2 Car, BD+11°3479, HD 170469, HIP 90593, SAO 103765, 2MASS J18291097+1141437, Gaia DR2 4484013343859055744[8] | |
| Database references | |
| SIMBAD | data |
The primary, component A, is a G-type main-sequence star with a stellar classification of G5V,[3] indicating it is generating energy through core hydrogen fusion. Estimates of the star's age range from five[2] to almost nine[6] billion years. It has 1.10 times the mass of the Sun and 1.24 times the Sun's radius.[5] The star has a higher than solar metallicity.[3] It is radiating 1.64[1] times the Sun's luminosity from its photosphere at an effective temperature of 5,786 K.[3]
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.[3] Initially it was thought to be a red dwarf of spectral class M1,[4] but was later determined to be a K-type main-sequence star with a class of K5V.[3] This star lies at a projected separation of 2708 AU[4] from the primary, and is orbiting with an estimated period of around 114,000 years.[7]
Planetary system
In 2007, a planet was discovered by the N2K Consortium, led by principal investigators Debra Fischer and Gregory P. Laughlin.[9] It was spotted using the radial velocity method, and was independently confirmed in 2014.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >0.67 MJ | 2.24 | 1,143 | 0.11 | — | — |