K2-194 b
Astrophysical Synthesis & Habitability Characterization
K2-194 b is a confirmed sub-neptune exoplanet orbiting the star K2-194, located approximately 2053.2 light-years (629.51 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0679% across the stellar disk), this world measures 3.642 Earth radii (0.32 Jupiter radii) and has a measured mass of 12.9 Earth masses. Combining its mass and radius yields a mean bulk density of 1.47 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.97 g⊕ (9.51 m/s²), and an escape velocity of 21.1 km/s.
In its orbital architecture around K2-194, K2-194 b completes one full revolution every 39.721 Earth days.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 3.642 R⊕, K2-194 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star K2-194 is classified as a stellar host with an effective photospheric temperature of 5,979 K, a radius of 1.2811 R☉, a mass of 1.1101 M☉, an estimated bolometric luminosity of 1.882 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, K2-194 shines at apparent V-band magnitude 12.998 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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 | K2-194 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,979 K |
| Stellar Radius | 1.2811 R☉ |
| Stellar Mass | 1.1101 M☉ |
| Bolometric Luminosity | 1.882 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.998 · G: 12.838 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 39.721 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.0653° |
| Mean Bulk Density | 1.47 g/cm³ (21.1 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2053.200 LY (629.510 pc) |