Kepler-301 d
Astrophysical Synthesis & Habitability Characterization
Kepler-301 d is a confirmed super-earth exoplanet orbiting the star Kepler-301, located approximately 2345.6 light-years (719.17 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0318% across the stellar disk), this world measures 1.75 Earth radii and has a measured mass of 3.71 Earth masses. Combining its mass and radius yields a mean bulk density of 3.82 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.21 g⊕ (11.87 m/s²), and an escape velocity of 16.3 km/s.
In its orbital architecture around Kepler-301, Kepler-301 d completes one full revolution every 13.751 Earth days at a semi-major axis of 0.112 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 88.6 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 725 K (+452°C / +846°F) and receiving 68.93 S⊕ (~93,815 W/m²), Kepler-301 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-301 is classified as a stellar host with an effective photospheric temperature of 5,815 K, a radius of 0.9 R☉, a mass of 1.022 M☉, an estimated bolometric luminosity of 0.831 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.45 Gyr and a metallicity of [Fe/H] = 0.187 dex (metal-rich relative to the Sun). From Earth, Kepler-301 shines at apparent V-band magnitude 14.458 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-301 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-301 d sharing its stellar neighborhood alongside Kepler-301 b, Kepler-301 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-301 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,815 K |
| Stellar Radius | 0.9000 R☉ |
| Stellar Mass | 1.0220 M☉ |
| Bolometric Luminosity | 0.831 L☉ |
| Metallicity [Fe/H] | 0.187 dex |
| Stellar Age | 1.450 Gyr |
| Apparent Magnitude | V: 14.458 · G: 14.274 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.112000 AU |
| Orbital Period | 13.751 days |
| Mean Orbital Velocity | 88.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.2100° |
| Mean Bulk Density | 3.82 g/cm³ (16.3 km/s vesc) |
| Insolation Flux | 68.9310 S⊕ (~93,815 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2345.600 LY (719.166 pc) |