K2-215 b
Astrophysical Synthesis & Habitability Characterization
K2-215 b is a confirmed sub-neptune exoplanet orbiting the star K2-215, located approximately 1317.6 light-years (403.96 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0399% across the stellar disk), this world measures 2.124 Earth radii and has a measured mass of 5.16 Earth masses. Combining its mass and radius yields a mean bulk density of 2.97 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.14 g⊕ (11.18 m/s²), and an escape velocity of 17.4 km/s.
In its orbital architecture around K2-215, K2-215 b completes one full revolution every 8.27 Earth days.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for K2-215 b place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star K2-215 is classified as a stellar host with an effective photospheric temperature of 5,704 K, a radius of 0.9744 R☉, a mass of 1 M☉, an estimated bolometric luminosity of 0.902 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.11 dex (metal-rich relative to the Sun). From Earth, K2-215 shines at apparent V-band magnitude 12.99 (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 | K2-215 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,704 K |
| Stellar Radius | 0.9744 R☉ |
| Stellar Mass | 1.0000 M☉ |
| Bolometric Luminosity | 0.902 L☉ |
| Metallicity [Fe/H] | 0.110 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.990 · G: 12.830 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 8.27 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.9842° |
| Mean Bulk Density | 2.97 g/cm³ (17.4 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1317.600 LY (403.964 pc) |