K2-332 b
Astrophysical Synthesis & Habitability Characterization
K2-332 b is a confirmed sub-neptune exoplanet orbiting the star K2-332, located approximately 401.8 light-years (123.2 parsecs) from the Solar System. First announced in 2021 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.5189% across the stellar disk), this world measures 2.2 Earth radii and has a measured mass of 5.48 Earth masses. Combining its mass and radius yields a mean bulk density of 2.84 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.13 g⊕ (11.08 m/s²), and an escape velocity of 17.7 km/s.
In its orbital architecture around K2-332, K2-332 b completes one full revolution every 17.706 Earth days.
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 266 K (-7°C / +19°F), K2-332 b orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star K2-332 is classified as a stellar host with an effective photospheric temperature of 3,315 K, a radius of 0.28 R☉, a mass of 0.27 M☉, an estimated bolometric luminosity of 0.00849 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, K2-332 shines at apparent Gaia G-band magnitude 16.479 (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 | K2-332 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,315 K |
| Stellar Radius | 0.2800 R☉ |
| Stellar Mass | 0.2700 M☉ |
| Bolometric Luminosity | 0.00849 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | — |
| Apparent Magnitude | · G: 16.479 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 17.706 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.84 g/cm³ (17.7 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 401.800 LY (123.202 pc) |