Kepler-407 b
Astrophysical Synthesis & Habitability Characterization
Kepler-407 b is a confirmed terrestrial exoplanet orbiting the star Kepler-407, located approximately 1103.6 light-years (338.37 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.011% across the stellar disk), this world measures 1.19 Earth radii and has a measured mass of 1.93 Earth masses. Combining its mass and radius yields a mean bulk density of 6.32 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.36 g⊕ (13.34 m/s²), and an escape velocity of 14.2 km/s.
In its orbital architecture around Kepler-407, Kepler-407 b completes one full revolution every 0.669 Earth days at a semi-major axis of 0.01531 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 248.9 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 1983 K (+1710°C / +3110°F) and receiving 4,102.01 S⊕ (~5,582,833 W/m²), Kepler-407 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-407 is classified as a solar-type yellow star of spectral type G with an effective photospheric temperature of 5,487 K, a radius of 1.04 R☉, a mass of 0.99 M☉, an estimated bolometric luminosity of 0.88 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.35 dex (metal-rich relative to the Sun). From Earth, Kepler-407 shines at apparent V-band magnitude 12.603 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-407 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-407 b sharing its stellar neighborhood alongside Kepler-407 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-407 |
| Spectral Type | G |
| Effective Temp (Teff) | 5,487 K |
| Stellar Radius | 1.0400 R☉ |
| Stellar Mass | 0.9900 M☉ |
| Bolometric Luminosity | 0.88 L☉ |
| Metallicity [Fe/H] | 0.350 dex |
| Stellar Age | 2.880 Gyr |
| Apparent Magnitude | V: 12.603 · G: 12.507 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.015310 AU |
| Orbital Period | 0.669 days |
| Mean Orbital Velocity | 248.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.1900° |
| Mean Bulk Density | 6.32 g/cm³ (14.2 km/s vesc) |
| Insolation Flux | 4102.0080 S⊕ (~5,582,833 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1103.600 LY (338.368 pc) |