K2-408 b
Astrophysical Synthesis & Habitability Characterization
K2-408 b is a confirmed super-earth exoplanet orbiting the star K2-408, located approximately 529.4 light-years (162.31 parsecs) from the Solar System. First announced in 2022 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0385% across the stellar disk), this world measures 1.677 Earth radii and has a measured mass of 3.45 Earth masses. Combining its mass and radius yields a mean bulk density of 4.03 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 16 km/s.
In its orbital architecture around K2-408, K2-408 b completes one full revolution every 20.979 Earth days.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for K2-408 b place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star K2-408 is classified as a solar-type yellow star of spectral type G7 with an effective photospheric temperature of 5,335 K, a radius of 0.784 R☉, a mass of 0.813 M☉, an estimated bolometric luminosity of 0.447 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.171 dex (metal-poor relative to the Sun). From Earth, K2-408 shines at apparent V-band magnitude 12.056 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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 | K2-408 |
| Spectral Type | G7 |
| Effective Temp (Teff) | 5,335 K |
| Stellar Radius | 0.7840 R☉ |
| Stellar Mass | 0.8130 M☉ |
| Bolometric Luminosity | 0.447 L☉ |
| Metallicity [Fe/H] | -0.171 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.056 · G: 11.735 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 20.979 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.03 g/cm³ (16 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 529.400 LY (162.306 pc) |