Kepler-105 b
Astrophysical Synthesis & Habitability Characterization
Kepler-105 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-105, located approximately 1497.8 light-years (459.22 parsecs) from the Solar System. First announced in 2013 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0511% across the stellar disk), this world measures 2.53 Earth radii and has a measured mass of 10.8 Earth masses. Combining its mass and radius yields a mean bulk density of 3.68 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.69 g⊕ (16.57 m/s²), and an escape velocity of 23.1 km/s.
In its orbital architecture around Kepler-105, Kepler-105 b completes one full revolution every 5.412 Earth days at a semi-major axis of 0.06016 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 120.9 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.02 (ranging from 0.059 AU at periapsis to 0.0614 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1418 K (+1145°C / +2093°F) and receiving 341.81 S⊕ (~465,202 W/m²), Kepler-105 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-105 is classified as a stellar host with an effective photospheric temperature of 5,933 K, a radius of 1.026 R☉, a mass of 0.991 M☉, an estimated bolometric luminosity of 1.17 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = -0.09 dex (near-solar heavy-element abundance). From Earth, Kepler-105 shines at apparent V-band magnitude 12.981 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-105 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-105 b sharing its stellar neighborhood alongside Kepler-105 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-105 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,933 K |
| Stellar Radius | 1.0260 R☉ |
| Stellar Mass | 0.9910 M☉ |
| Bolometric Luminosity | 1.17 L☉ |
| Metallicity [Fe/H] | -0.090 dex |
| Stellar Age | 4.270 Gyr |
| Apparent Magnitude | V: 12.981 · G: 12.803 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.060160 AU |
| Orbital Period | 5.412 days |
| Mean Orbital Velocity | 120.9 km/s |
| Orbital Eccentricity (e) | 0.02000 |
| Orbital Inclination (i) | 85.9400° |
| Mean Bulk Density | 3.68 g/cm³ (23.1 km/s vesc) |
| Insolation Flux | 341.8090 S⊕ (~465,202 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1497.800 LY (459.223 pc) |