K2-412 b
Astrophysical Synthesis & Habitability Characterization
K2-412 b is a confirmed sub-neptune exoplanet orbiting the star K2-412, located approximately 2133.3 light-years (654.09 parsecs) from the Solar System. First announced in 2022 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0394% across the stellar disk), this world measures 2.116 Earth radii and has a measured mass of 5.13 Earth masses. Combining its mass and radius yields a mean bulk density of 2.99 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.15 g⊕ (11.28 m/s²), and an escape velocity of 17.4 km/s.
In its orbital architecture around K2-412, K2-412 b completes one full revolution every 5.938 Earth days at a semi-major axis of 0.0586 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 107.4 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1101 K (+828°C / +1522°F) and receiving 243.52 S⊕ (~331,428 W/m²), K2-412 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-412 is classified as a stellar host with an effective photospheric temperature of 5,590 K, a radius of 0.977 R☉, a mass of 0.893 M☉, an estimated bolometric luminosity of 0.836 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.014 dex (near-solar heavy-element abundance). From Earth, K2-412 shines at apparent V-band magnitude 15.746 (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: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | K2-412 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,590 K |
| Stellar Radius | 0.9770 R☉ |
| Stellar Mass | 0.8930 M☉ |
| Bolometric Luminosity | 0.836 L☉ |
| Metallicity [Fe/H] | 0.014 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 15.746 · G: 15.149 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.058600 AU |
| Orbital Period | 5.938 days |
| Mean Orbital Velocity | 107.4 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.9980° |
| Mean Bulk Density | 2.99 g/cm³ (17.4 km/s vesc) |
| Insolation Flux | 243.5180 S⊕ (~331,428 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2133.300 LY (654.085 pc) |