K2-193 b
Astrophysical Synthesis & Habitability Characterization
K2-193 b is a confirmed sub-neptune exoplanet orbiting the star K2-193, located approximately 1343.5 light-years (411.92 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.1365% across the stellar disk), this world measures 3.95 Earth radii (0.35 Jupiter radii) and has a measured mass of 14.8 Earth masses. Combining its mass and radius yields a mean bulk density of 1.32 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.95 g⊕ (9.32 m/s²), and an escape velocity of 21.7 km/s.
In its orbital architecture around K2-193, K2-193 b completes one full revolution every 14.787 Earth days at a semi-major axis of 0.1184 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 87.1 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 739 K (+466°C / +871°F) and receiving 59.92 S⊕ (~81,552 W/m²), K2-193 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-193 is classified as a stellar host with an effective photospheric temperature of 5,817 K, a radius of 0.98 R☉, a mass of 1.01 M☉, an estimated bolometric luminosity of 0.987 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, K2-193 shines at apparent V-band magnitude 13.341 (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 | K2-193 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,817 K |
| Stellar Radius | 0.9800 R☉ |
| Stellar Mass | 1.0100 M☉ |
| Bolometric Luminosity | 0.987 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 13.341 · G: 13.095 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.118400 AU |
| Orbital Period | 14.787 days |
| Mean Orbital Velocity | 87.1 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.1926° |
| Mean Bulk Density | 1.32 g/cm³ (21.7 km/s vesc) |
| Insolation Flux | 59.9210 S⊕ (~81,552 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1343.500 LY (411.923 pc) |