Kepler-234 b
Astrophysical Synthesis & Habitability Characterization
Kepler-234 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-234, located approximately 5652.6 light-years (1733.1 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0929% across the stellar disk), this world measures 3.7 Earth radii (0.33 Jupiter radii) and has a measured mass of 13.2 Earth masses. Combining its mass and radius yields a mean bulk density of 1.44 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.96 g⊕ (9.41 m/s²), and an escape velocity of 21.1 km/s.
In its orbital architecture around Kepler-234, Kepler-234 b completes one full revolution every 2.712 Earth days at a semi-major axis of 0.04 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 160.5 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 1420 K (+1147°C / +2097°F) and receiving 1,007.72 S⊕ (~1,371,501 W/m²), Kepler-234 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-234 is classified as a stellar host with an effective photospheric temperature of 6,224 K, a radius of 1.113 R☉, a mass of 1.129 M☉, an estimated bolometric luminosity of 1.668 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.22 dex (metal-rich relative to the Sun). From Earth, Kepler-234 shines at apparent V-band magnitude 15.747 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-234 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-234 b sharing its stellar neighborhood alongside Kepler-234 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-234 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,224 K |
| Stellar Radius | 1.1130 R☉ |
| Stellar Mass | 1.1290 M☉ |
| Bolometric Luminosity | 1.668 L☉ |
| Metallicity [Fe/H] | 0.220 dex |
| Stellar Age | 2.880 Gyr |
| Apparent Magnitude | V: 15.747 · G: 15.501 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.040000 AU |
| Orbital Period | 2.712 days |
| Mean Orbital Velocity | 160.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.8100° |
| Mean Bulk Density | 1.44 g/cm³ (21.1 km/s vesc) |
| Insolation Flux | 1007.7160 S⊕ (~1,371,501 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 5652.600 LY (1733.100 pc) |