K2-324 b
Astrophysical Synthesis & Habitability Characterization
K2-324 b is a confirmed sub-neptune exoplanet orbiting the star K2-324, located approximately 445.7 light-years (136.67 parsecs) from the Solar System. First announced in 2020 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.1946% across the stellar disk), this world measures 2.43 Earth radii and has a measured mass of 6.48 Earth masses. Combining its mass and radius yields a mean bulk density of 2.49 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 18.3 km/s.
In its orbital architecture around K2-324, K2-324 b completes one full revolution every 3.262 Earth days at a semi-major axis of 0.0331 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 110.4 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 707 K (+434°C / +813°F) and receiving 42.39 S⊕ (~57,697 W/m²), K2-324 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-324 is classified as a stellar host with an effective photospheric temperature of 3,752 K, a radius of 0.505 R☉, a mass of 0.517 M☉, an estimated bolometric luminosity of 0.045 L☉. From Earth, K2-324 shines at apparent V-band magnitude 15.223 (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 | K2-324 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,752 K |
| Stellar Radius | 0.5050 R☉ |
| Stellar Mass | 0.5170 M☉ |
| Bolometric Luminosity | 0.045 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 15.223 · G: 14.517 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.033100 AU |
| Orbital Period | 3.262 days |
| Mean Orbital Velocity | 110.4 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.3300° |
| Mean Bulk Density | 2.49 g/cm³ (18.3 km/s vesc) |
| Insolation Flux | 42.3931 S⊕ (~57,697 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 445.700 LY (136.667 pc) |