K2-232 b
Astrophysical Synthesis & Habitability Characterization
K2-232 b is a confirmed gas giant exoplanet orbiting the star K2-232, located approximately 426.4 light-years (130.72 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.7757% across the stellar disk), this world measures 11.624 Earth radii (1.04 Jupiter radii) and has a measured mass of 135.713 Earth masses (0.43 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.48 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1 g⊕ (9.81 m/s²), and an escape velocity of 38.2 km/s.
In its orbital architecture around K2-232, K2-232 b completes one full revolution every 11.168 Earth days at a semi-major axis of 0.1016 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 99 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.245 carries the world between 0.0767 AU at periapsis and 0.1265 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1001 K (+728°C / +1342°F) and receiving 312.16 S⊕ (~424,843 W/m²), K2-232 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-232 is classified as a warm F-type star of spectral type F with an effective photospheric temperature of 6,100 K, a radius of 1.21 R☉, a mass of 1.121 M☉, an estimated bolometric luminosity of 1.819 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.9 Gyr and a metallicity of [Fe/H] = 0.106 dex (metal-rich relative to the Sun). From Earth, K2-232 shines at apparent V-band magnitude 9.822 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The K2-232 system is a multi-planet architecture hosting 2 confirmed worlds, with K2-232 b sharing its stellar neighborhood alongside K2-232 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: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | K2-232 |
| Spectral Type | F |
| Effective Temp (Teff) | 6,100 K |
| Stellar Radius | 1.2100 R☉ |
| Stellar Mass | 1.1210 M☉ |
| Bolometric Luminosity | 1.819 L☉ |
| Metallicity [Fe/H] | 0.106 dex |
| Stellar Age | 3.900 Gyr |
| Apparent Magnitude | V: 9.822 · G: 9.726 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.101600 AU |
| Orbital Period | 11.168 days |
| Mean Orbital Velocity | 99 km/s |
| Orbital Eccentricity (e) | 0.24500 |
| Orbital Inclination (i) | 89.8300° |
| Mean Bulk Density | 0.48 g/cm³ (38.2 km/s vesc) |
| Insolation Flux | 312.1550 S⊕ (~424,843 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 426.400 LY (130.720 pc) |