Kepler-164 e
Astrophysical Synthesis & Habitability Characterization
Kepler-164 e is a confirmed sub-neptune exoplanet orbiting the star Kepler-164, located approximately 2905.3 light-years (890.76 parsecs) from the Solar System. First announced in 2023 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1256% across the stellar disk), this world measures 4.24 Earth radii (0.38 Jupiter radii) and has a measured mass of 16.7 Earth masses. Combining its mass and radius yields a mean bulk density of 1.21 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.93 g⊕ (9.12 m/s²), and an escape velocity of 22.2 km/s.
In its orbital architecture around Kepler-164, Kepler-164 e completes one full revolution every 94.887 Earth days at a semi-major axis of 0.4025 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 46.1 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.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 429 K (+156°C / +313°F) and receiving 7.99 S⊕ (~10,874 W/m²), Kepler-164 e orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-164 is classified as a stellar host with an effective photospheric temperature of 5,888 K, a radius of 1.097 R☉, a mass of 0.966 M☉, an estimated bolometric luminosity of 1.298 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.62 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, Kepler-164 shines at apparent V-band magnitude 14.379 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-164 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-164 e sharing its stellar neighborhood alongside Kepler-164 b, Kepler-164 c, Kepler-164 d.
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-164 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,888 K |
| Stellar Radius | 1.0970 R☉ |
| Stellar Mass | 0.9660 M☉ |
| Bolometric Luminosity | 1.298 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | 0.620 Gyr |
| Apparent Magnitude | V: 14.379 · G: 14.233 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.402500 AU |
| Orbital Period | 94.887 days |
| Mean Orbital Velocity | 46.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.3700° |
| Mean Bulk Density | 1.21 g/cm³ (22.2 km/s vesc) |
| Insolation Flux | 7.9900 S⊕ (~10,874 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2905.300 LY (890.758 pc) |