Kepler-393 b
Astrophysical Synthesis & Habitability Characterization
Kepler-393 b is a confirmed super-earth exoplanet orbiting the star Kepler-393, located approximately 2874.8 light-years (881.4 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0073% across the stellar disk), this world measures 1.29 Earth radii and has a measured mass of 2.21 Earth masses. Combining its mass and radius yields a mean bulk density of 5.68 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.33 g⊕ (13.04 m/s²), and an escape velocity of 14.6 km/s.
In its orbital architecture around Kepler-393, Kepler-393 b completes one full revolution every 9.182 Earth days at a semi-major axis of 0.091 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 107.8 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 1052 K (+779°C / +1434°F) and receiving 429.81 S⊕ (~584,975 W/m²), Kepler-393 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-393 is classified as a stellar host with an effective photospheric temperature of 6,189 K, a radius of 1.382 R☉, a mass of 1.256 M☉, an estimated bolometric luminosity of 2.514 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.82 Gyr and a metallicity of [Fe/H] = 0.032 dex (near-solar heavy-element abundance). From Earth, Kepler-393 shines at apparent V-band magnitude 13.258 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-393 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-393 b sharing its stellar neighborhood alongside Kepler-393 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-393 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,189 K |
| Stellar Radius | 1.3820 R☉ |
| Stellar Mass | 1.2560 M☉ |
| Bolometric Luminosity | 2.514 L☉ |
| Metallicity [Fe/H] | 0.032 dex |
| Stellar Age | 2.820 Gyr |
| Apparent Magnitude | V: 13.258 · G: 13.178 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.091000 AU |
| Orbital Period | 9.182 days |
| Mean Orbital Velocity | 107.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.0700° |
| Mean Bulk Density | 5.68 g/cm³ (14.6 km/s vesc) |
| Insolation Flux | 429.8130 S⊕ (~584,975 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2874.800 LY (881.404 pc) |