K2-323 b
Astrophysical Synthesis & Habitability Characterization
K2-323 b is a confirmed sub-neptune exoplanet orbiting the star K2-323, located approximately 385.9 light-years (118.32 parsecs) from the Solar System. First announced in 2020 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.123% across the stellar disk), this world measures 2.1 Earth radii and has a measured mass of 5.06 Earth masses. Combining its mass and radius yields a mean bulk density of 3.01 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 K2-323, K2-323 b completes one full revolution every 24.93 Earth days at a semi-major axis of 0.1275 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 55.6 km/s (compared to Earth's 29.8 km/s).
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 318 K (+45°C / +113°F) and an incident stellar irradiance of 2.82 S⊕ (~3,833 W/m²), K2-323 b orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star K2-323 is classified as a stellar host with an effective photospheric temperature of 3,710 K, a radius of 0.549 R☉, a mass of 0.478 M☉, an estimated bolometric luminosity of 0.051 L☉. From Earth, K2-323 shines at apparent V-band magnitude 14.935 (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 | K2-323 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,710 K |
| Stellar Radius | 0.5490 R☉ |
| Stellar Mass | 0.4780 M☉ |
| Bolometric Luminosity | 0.051 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 14.935 · G: 14.069 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.127500 AU |
| Orbital Period | 24.93 days |
| Mean Orbital Velocity | 55.6 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.8800° |
| Mean Bulk Density | 3.01 g/cm³ (17.4 km/s vesc) |
| Insolation Flux | 2.8163 S⊕ (~3,833 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 385.900 LY (118.318 pc) |