Kepler-169 f
Astrophysical Synthesis & Habitability Characterization
Kepler-169 f is a confirmed sub-neptune exoplanet orbiting the star Kepler-169, located approximately 1325.9 light-years (406.53 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0961% across the stellar disk), this world measures 2.58 Earth radii and has a measured mass of 7.18 Earth masses. Combining its mass and radius yields a mean bulk density of 2.31 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.08 g⊕ (10.59 m/s²), and an escape velocity of 18.7 km/s.
In its orbital architecture around Kepler-169, Kepler-169 f completes one full revolution every 87.09 Earth days at a semi-major axis of 0.359 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 44.8 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 2.580 R⊕, Kepler-169 f exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star Kepler-169 is classified as a stellar host with an effective photospheric temperature of 4,997 K, a radius of 0.763 R☉, a mass of 0.825 M☉, an estimated bolometric luminosity of 0.326 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.79 Gyr and a metallicity of [Fe/H] = 0.17 dex (metal-rich relative to the Sun). From Earth, Kepler-169 shines at apparent V-band magnitude 14.424 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-169 system is a multi-planet architecture hosting 5 confirmed worlds, with Kepler-169 f sharing its stellar neighborhood alongside Kepler-169 b, Kepler-169 c, Kepler-169 d, Kepler-169 e.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-169 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,997 K |
| Stellar Radius | 0.7630 R☉ |
| Stellar Mass | 0.8250 M☉ |
| Bolometric Luminosity | 0.326 L☉ |
| Metallicity [Fe/H] | 0.170 dex |
| Stellar Age | 0.790 Gyr |
| Apparent Magnitude | V: 14.424 · G: 14.162 |
| System Architecture | 1 Star, 5 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.359000 AU |
| Orbital Period | 87.09 days |
| Mean Orbital Velocity | 44.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.1500° |
| Mean Bulk Density | 2.31 g/cm³ (18.7 km/s vesc) |
| Insolation Flux | 2.4390 S⊕ (~3,319 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1325.900 LY (406.529 pc) |