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 in about 959,000 years.
The primary, component A, is a G-type subgiant with a stellar classification of G5IV, 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 along a position angle of 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 from the primary, and is orbiting with an estimated period of around 114,000 years.
Planetary system In 2007, a gas giant exoplanet was discovered around the primary star by the N2K Consortium, led by principal investigators Debra Fischer and Gregory P. Laughlin. It was spotted using the radial velocity method, and was independently confirmed in 2014. Its minimum mass is a third that of Jupiter, and it orbits at just over twice Earth's distance from the Sun, taking three Earth years to complete an orbit.
A 2026 study using HARPS-N found weak evidence for a potential candidate second planet, which would be a hot Neptune orbiting with an 8-day period.
See also HD 125612 HD 231701 HD 17156 HD 11506 List of extrasolar planets
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