Kepler-30 b
Astrophysical Synthesis & Habitability Characterization
Kepler-30 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-30, located approximately 2981.8 light-years (914.22 parsecs) from the Solar System. First announced in 2012 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1417% across the stellar disk), this world measures 3.9 Earth radii (0.35 Jupiter radii) and has a measured mass of 11.3 Earth masses. Combining its mass and radius yields a mean bulk density of 1.05 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.74 g⊕ (7.26 m/s²), and an escape velocity of 19 km/s.
In its orbital architecture around Kepler-30, Kepler-30 b completes one full revolution every 29.334 Earth days at a semi-major axis of 0.18 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 66.8 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.042 (ranging from 0.1724 AU at periapsis to 0.1876 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 524 K (+251°C / +484°F) and receiving 16.38 S⊕ (~22,292 W/m²), Kepler-30 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-30 is classified as a stellar host with an effective photospheric temperature of 5,498 K, a radius of 0.95 R☉, a mass of 0.99 M☉, an estimated bolometric luminosity of 0.74 L☉. Stellar evolution modeling indicates an estimated stellar age of 2 Gyr and a metallicity of [Fe/H] = 0.18 dex (metal-rich relative to the Sun). From Earth, Kepler-30 shines at apparent V-band magnitude 15.726 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-30 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-30 b sharing its stellar neighborhood alongside Kepler-30 c, Kepler-30 d.
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-30 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,498 K |
| Stellar Radius | 0.9500 R☉ |
| Stellar Mass | 0.9900 M☉ |
| Bolometric Luminosity | 0.74 L☉ |
| Metallicity [Fe/H] | 0.180 dex |
| Stellar Age | 2.000 Gyr |
| Apparent Magnitude | V: 15.726 · G: 15.376 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.180000 AU |
| Orbital Period | 29.334 days |
| Mean Orbital Velocity | 66.8 km/s |
| Orbital Eccentricity (e) | 0.04200 |
| Orbital Inclination (i) | 90.1790° |
| Mean Bulk Density | 1.05 g/cm³ (19 km/s vesc) |
| Insolation Flux | 16.3790 S⊕ (~22,292 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2981.800 LY (914.221 pc) |