Kepler-46 d
Astrophysical Synthesis & Habitability Characterization
Kepler-46 d is a confirmed super-earth exoplanet orbiting the star Kepler-46, located approximately 2534.4 light-years (777.06 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0362% across the stellar disk), this world measures 1.64 Earth radii and has a measured mass of 3.33 Earth masses. Combining its mass and radius yields a mean bulk density of 4.16 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.24 g⊕ (12.16 m/s²), and an escape velocity of 15.9 km/s.
In its orbital architecture around Kepler-46, Kepler-46 d completes one full revolution every 6.767 Earth days at a semi-major axis of 0.067 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 107.7 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 845 K (+572°C / +1062°F) and receiving 92.35 S⊕ (~125,683 W/m²), Kepler-46 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-46 is classified as an orange K-type star of spectral type K with an effective photospheric temperature of 5,309 K, a radius of 0.79 R☉, a mass of 0.883 M☉, an estimated bolometric luminosity of 0.445 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.34 Gyr and a metallicity of [Fe/H] = 0.17 dex (metal-rich relative to the Sun). From Earth, Kepler-46 shines at apparent V-band magnitude 15.312 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-46 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-46 d sharing its stellar neighborhood alongside Kepler-46 b, Kepler-46 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-46 |
| Spectral Type | K |
| Effective Temp (Teff) | 5,309 K |
| Stellar Radius | 0.7900 R☉ |
| Stellar Mass | 0.8830 M☉ |
| Bolometric Luminosity | 0.445 L☉ |
| Metallicity [Fe/H] | 0.170 dex |
| Stellar Age | 2.340 Gyr |
| Apparent Magnitude | V: 15.312 · G: 15.255 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.067000 AU |
| Orbital Period | 6.767 days |
| Mean Orbital Velocity | 107.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.5100° |
| Mean Bulk Density | 4.16 g/cm³ (15.9 km/s vesc) |
| Insolation Flux | 92.3460 S⊕ (~125,683 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2534.400 LY (777.060 pc) |