Kepler-352 d
Astrophysical Synthesis & Habitability Characterization
Kepler-352 d is a confirmed terrestrial exoplanet orbiting the star Kepler-352, located approximately 824.3 light-years (252.73 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0092% across the stellar disk), this world measures 0.806 Earth radii and has a measured mass of 0.449 Earth masses. Combining its mass and radius yields a mean bulk density of 4.73 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.69 g⊕ (6.77 m/s²), and an escape velocity of 8.3 km/s.
In its orbital architecture around Kepler-352, Kepler-352 d completes one full revolution every 6.887 Earth days at a semi-major axis of 0.06574 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 103.8 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.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 788 K (+515°C / +959°F) and receiving 81.30 S⊕ (~110,649 W/m²), Kepler-352 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-352 is classified as a stellar host with an effective photospheric temperature of 5,208 K, a radius of 0.772 R☉, a mass of 0.796 M☉, an estimated bolometric luminosity of 0.393 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.7 Gyr and a metallicity of [Fe/H] = -0.14 dex (metal-poor relative to the Sun). From Earth, Kepler-352 shines at apparent V-band magnitude 13.142 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-352 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-352 d sharing its stellar neighborhood alongside Kepler-352 b, Kepler-352 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-352 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,208 K |
| Stellar Radius | 0.7720 R☉ |
| Stellar Mass | 0.7960 M☉ |
| Bolometric Luminosity | 0.393 L☉ |
| Metallicity [Fe/H] | -0.140 dex |
| Stellar Age | 1.700 Gyr |
| Apparent Magnitude | V: 13.142 · G: 12.956 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.065740 AU |
| Orbital Period | 6.887 days |
| Mean Orbital Velocity | 103.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.6600° |
| Mean Bulk Density | 4.73 g/cm³ (8.3 km/s vesc) |
| Insolation Flux | 81.3000 S⊕ (~110,649 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 824.300 LY (252.733 pc) |