K2-336 b
Astrophysical Synthesis & Habitability Characterization
K2-336 b is a confirmed terrestrial exoplanet orbiting the star K2-336, located approximately 780.5 light-years (239.29 parsecs) from the Solar System. First announced in 2021 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0195% across the stellar disk), this world measures 1.22 Earth radii and has a measured mass of 1.98 Earth masses. Combining its mass and radius yields a mean bulk density of 6.01 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.33 g⊕ (13.04 m/s²), and an escape velocity of 14.3 km/s.
In its orbital architecture around K2-336, K2-336 b completes one full revolution every 21.195 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 569 K (+296°C / +565°F), K2-336 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-336 is classified as a stellar host with an effective photospheric temperature of 5,424 K, a radius of 0.8 R☉, a mass of 0.86 M☉, an estimated bolometric luminosity of 0.497 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.17 dex (metal-poor relative to the Sun). From Earth, K2-336 shines at apparent V-band magnitude 12.803 (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 | K2-336 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,424 K |
| Stellar Radius | 0.8000 R☉ |
| Stellar Mass | 0.8600 M☉ |
| Bolometric Luminosity | 0.497 L☉ |
| Metallicity [Fe/H] | -0.170 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.803 · G: 12.511 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 21.195 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.0304° |
| Mean Bulk Density | 6.01 g/cm³ (14.3 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 780.500 LY (239.289 pc) |