Kepler-227 b
Astrophysical Synthesis & Habitability Characterization
Kepler-227 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-227, located approximately 3532.5 light-years (1083.06 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0683% across the stellar disk), this world measures 3.11 Earth radii (0.28 Jupiter radii) and has a measured mass of 9.85 Earth masses. Combining its mass and radius yields a mean bulk density of 1.81 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.02 g⊕ (10 m/s²), and an escape velocity of 19.9 km/s.
In its orbital architecture around Kepler-227, Kepler-227 b completes one full revolution every 9.488 Earth days at a semi-major axis of 0.09 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 103.2 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 793 K (+520°C / +968°F) and receiving 104.64 S⊕ (~142,416 W/m²), Kepler-227 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-227 is classified as a stellar host with an effective photospheric temperature of 5,854 K, a radius of 1.091 R☉, a mass of 0.954 M☉, an estimated bolometric luminosity of 1.254 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.98 Gyr and a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, Kepler-227 shines at apparent V-band magnitude 15.623 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-227 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-227 b sharing its stellar neighborhood alongside Kepler-227 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-227 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,854 K |
| Stellar Radius | 1.0910 R☉ |
| Stellar Mass | 0.9540 M☉ |
| Bolometric Luminosity | 1.254 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | 3.980 Gyr |
| Apparent Magnitude | V: 15.623 · G: 15.323 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.090000 AU |
| Orbital Period | 9.488 days |
| Mean Orbital Velocity | 103.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.6600° |
| Mean Bulk Density | 1.81 g/cm³ (19.9 km/s vesc) |
| Insolation Flux | 104.6410 S⊕ (~142,416 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3532.500 LY (1083.060 pc) |