K2-339 b
Astrophysical Synthesis & Habitability Characterization
K2-339 b is a confirmed super-earth exoplanet orbiting the star K2-339, located approximately 1175.3 light-years (360.36 parsecs) from the Solar System. First announced in 2021 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0598% across the stellar disk), this world measures 1.92 Earth radii and has a measured mass of 4.35 Earth masses. Combining its mass and radius yields a mean bulk density of 3.39 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.18 g⊕ (11.57 m/s²), and an escape velocity of 16.8 km/s.
In its orbital architecture around K2-339, K2-339 b completes one full revolution every 19.507 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 508 K (+235°C / +455°F), K2-339 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-339 is classified as a stellar host with an effective photospheric temperature of 4,857 K, a radius of 0.72 R☉, a mass of 0.74 M☉, an estimated bolometric luminosity of 0.259 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.11 dex (metal-poor relative to the Sun). From Earth, K2-339 shines at apparent V-band magnitude 14.487 (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 | K2-339 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,857 K |
| Stellar Radius | 0.7200 R☉ |
| Stellar Mass | 0.7400 M☉ |
| Bolometric Luminosity | 0.259 L☉ |
| Metallicity [Fe/H] | -0.110 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 14.487 · G: 14.344 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 19.507 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 3.39 g/cm³ (16.8 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1175.300 LY (360.360 pc) |