Kepler-151 b
Astrophysical Synthesis & Habitability Characterization
Kepler-151 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-151, located approximately 2119.7 light-years (649.92 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1142% across the stellar disk), this world measures 3.06 Earth radii (0.27 Jupiter radii) and has a measured mass of 9.59 Earth masses. Combining its mass and radius yields a mean bulk density of 1.85 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 19.8 km/s.
In its orbital architecture around Kepler-151, Kepler-151 b completes one full revolution every 15.229 Earth days at a semi-major axis of 0.116 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 82.9 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 639 K (+366°C / +691°F) and receiving 40.73 S⊕ (~55,431 W/m²), Kepler-151 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-151 is classified as a stellar host with an effective photospheric temperature of 5,460 K, a radius of 0.83 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.549 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.6 Gyr and a metallicity of [Fe/H] = 0.125 dex (metal-rich relative to the Sun). From Earth, Kepler-151 shines at apparent V-band magnitude 14.957 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-151 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-151 b sharing its stellar neighborhood alongside Kepler-151 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-151 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,460 K |
| Stellar Radius | 0.8300 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.549 L☉ |
| Metallicity [Fe/H] | 0.125 dex |
| Stellar Age | 4.600 Gyr |
| Apparent Magnitude | V: 14.957 · G: 14.719 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.116000 AU |
| Orbital Period | 15.229 days |
| Mean Orbital Velocity | 82.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.5400° |
| Mean Bulk Density | 1.85 g/cm³ (19.8 km/s vesc) |
| Insolation Flux | 40.7280 S⊕ (~55,431 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2119.700 LY (649.919 pc) |