Kepler-358 b
Astrophysical Synthesis & Habitability Characterization
Kepler-358 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-358, located approximately 3591.3 light-years (1101.1 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0683% across the stellar disk), this world measures 2.72 Earth radii and has a measured mass of 7.85 Earth masses. Combining its mass and radius yields a mean bulk density of 2.15 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.06 g⊕ (10.4 m/s²), and an escape velocity of 19 km/s.
In its orbital architecture around Kepler-358, Kepler-358 b completes one full revolution every 34.06 Earth days at a semi-major axis of 0.21 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 67.1 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 554 K (+281°C / +538°F) and receiving 21.81 S⊕ (~29,677 W/m²), Kepler-358 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-358 is classified as a stellar host with an effective photospheric temperature of 5,908 K, a radius of 0.954 R☉, a mass of 0.94 M☉, an estimated bolometric luminosity of 0.995 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.4 Gyr and a metallicity of [Fe/H] = 0.035 dex (near-solar heavy-element abundance). From Earth, Kepler-358 shines at apparent V-band magnitude 15.516 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-358 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-358 b sharing its stellar neighborhood alongside Kepler-358 c.
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-358 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,908 K |
| Stellar Radius | 0.9540 R☉ |
| Stellar Mass | 0.9400 M☉ |
| Bolometric Luminosity | 0.995 L☉ |
| Metallicity [Fe/H] | 0.035 dex |
| Stellar Age | 0.400 Gyr |
| Apparent Magnitude | V: 15.516 · G: 15.356 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.210000 AU |
| Orbital Period | 34.06 days |
| Mean Orbital Velocity | 67.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.3600° |
| Mean Bulk Density | 2.15 g/cm³ (19 km/s vesc) |
| Insolation Flux | 21.8050 S⊕ (~29,677 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3591.300 LY (1101.100 pc) |