Kepler-75 b
Astrophysical Synthesis & Habitability Characterization
Kepler-75 b is a confirmed gas giant exoplanet orbiting the star Kepler-75, located approximately 2724.6 light-years (835.36 parsecs) from the Solar System. First announced in 2013 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 1.47% across the stellar disk), this world measures 11.77 Earth radii (1.05 Jupiter radii) and has a measured mass of 3209.9 Earth masses (10.1 Jupiter masses). Combining its mass and radius yields a mean bulk density of 10.85 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 23.17 g⊕ (227.22 m/s²), and an escape velocity of 184.7 km/s.
In its orbital architecture around Kepler-75, Kepler-75 b completes one full revolution every 8.885 Earth days at a semi-major axis of 0.0818 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 100.2 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.57, swinging from 0.0352 AU at periapsis out to 0.1284 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 767 K (+494°C / +921°F) and receiving 106.48 S⊕ (~144,925 W/m²), Kepler-75 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-75 is classified as an orange K-type star of spectral type K0 V with an effective photospheric temperature of 5,200 K, a radius of 0.89 R☉, a mass of 0.91 M☉, an estimated bolometric luminosity of 0.52 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.2 Gyr and a metallicity of [Fe/H] = 0.3 dex (metal-rich relative to the Sun). From Earth, Kepler-75 shines at apparent V-band magnitude 15.414 (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-75 |
| Spectral Type | K0 V |
| Effective Temp (Teff) | 5,200 K |
| Stellar Radius | 0.8900 R☉ |
| Stellar Mass | 0.9100 M☉ |
| Bolometric Luminosity | 0.52 L☉ |
| Metallicity [Fe/H] | 0.300 dex |
| Stellar Age | 6.200 Gyr |
| Apparent Magnitude | V: 15.414 · G: 15.179 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.081800 AU |
| Orbital Period | 8.885 days |
| Mean Orbital Velocity | 100.2 km/s |
| Orbital Eccentricity (e) | 0.57000 |
| Orbital Inclination (i) | 89.1200° |
| Mean Bulk Density | 10.85 g/cm³ (184.7 km/s vesc) |
| Insolation Flux | 106.4840 S⊕ (~144,925 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2724.600 LY (835.356 pc) |