Kepler-912 b
Astrophysical Synthesis & Habitability Characterization
Kepler-912 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-912, located approximately 6538.5 light-years (2004.72 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0535% across the stellar disk), this world measures 2.8 Earth radii and has a measured mass of 8.25 Earth masses. Combining its mass and radius yields a mean bulk density of 2.07 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.05 g⊕ (10.3 m/s²), and an escape velocity of 19.2 km/s.
In its orbital architecture around Kepler-912, Kepler-912 b completes one full revolution every 2.535 Earth days at a semi-major axis of 0.0339 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 145.5 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 1218 K (+945°C / +1733°F) and receiving 519.95 S⊕ (~707,652 W/m²), Kepler-912 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-912 is classified as a stellar host with an effective photospheric temperature of 5,998 K, a radius of 1.11 R☉, a mass of 1.07 M☉, an estimated bolometric luminosity of 1.431 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.16 Gyr and a metallicity of [Fe/H] = 0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-912 shines at apparent V-band magnitude 15.668 (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-912 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,998 K |
| Stellar Radius | 1.1100 R☉ |
| Stellar Mass | 1.0700 M☉ |
| Bolometric Luminosity | 1.431 L☉ |
| Metallicity [Fe/H] | 0.020 dex |
| Stellar Age | 3.160 Gyr |
| Apparent Magnitude | V: 15.668 · G: 15.326 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.033900 AU |
| Orbital Period | 2.535 days |
| Mean Orbital Velocity | 145.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 68.6700° |
| Mean Bulk Density | 2.07 g/cm³ (19.2 km/s vesc) |
| Insolation Flux | 519.9500 S⊕ (~707,652 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 6538.500 LY (2004.720 pc) |