Kepler-434 b
Astrophysical Synthesis & Habitability Characterization
Kepler-434 b is a confirmed gas giant exoplanet orbiting the star Kepler-434, located approximately 3987.4 light-years (1222.54 parsecs) from the Solar System. First announced in 2015 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.7085% across the stellar disk), this world measures 12.67 Earth radii (1.13 Jupiter radii) and has a measured mass of 908.96 Earth masses (2.86 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.46 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 5.66 g⊕ (55.51 m/s²), and an escape velocity of 94.7 km/s.
In its orbital architecture around Kepler-434, Kepler-434 b completes one full revolution every 12.875 Earth days at a semi-major axis of 0.1143 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 96.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.131 carries the world between 0.0993 AU at periapsis and 0.1293 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1000 K (+727°C / +1341°F) and receiving 158.29 S⊕ (~215,426 W/m²), Kepler-434 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-434 is classified as a stellar host with an effective photospheric temperature of 5,977 K, a radius of 1.38 R☉, a mass of 1.198 M☉, an estimated bolometric luminosity of 2.181 L☉. Stellar evolution modeling indicates an estimated stellar age of 4 Gyr and a metallicity of [Fe/H] = 0.25 dex (metal-rich relative to the Sun). From Earth, Kepler-434 shines at apparent V-band magnitude 14.49 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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-434 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,977 K |
| Stellar Radius | 1.3800 R☉ |
| Stellar Mass | 1.1980 M☉ |
| Bolometric Luminosity | 2.181 L☉ |
| Metallicity [Fe/H] | 0.250 dex |
| Stellar Age | 4.000 Gyr |
| Apparent Magnitude | V: 14.490 · G: 14.500 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.114300 AU |
| Orbital Period | 12.875 days |
| Mean Orbital Velocity | 96.6 km/s |
| Orbital Eccentricity (e) | 0.13100 |
| Orbital Inclination (i) | 86.4600° |
| Mean Bulk Density | 2.46 g/cm³ (94.7 km/s vesc) |
| Insolation Flux | 158.2850 S⊕ (~215,426 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3987.400 LY (1222.540 pc) |