K2-65 b
Astrophysical Synthesis & Habitability Characterization
K2-65 b is a confirmed super-earth exoplanet orbiting the star K2-65, located approximately 235.5 light-years (72.2 parsecs) from the Solar System. First announced in 2016 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0297% across the stellar disk), this world measures 1.58 Earth radii and has a measured mass of 3.12 Earth masses. Combining its mass and radius yields a mean bulk density of 4.36 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.25 g⊕ (12.26 m/s²), and an escape velocity of 15.7 km/s.
In its orbital architecture around K2-65, K2-65 b completes one full revolution every 12.648 Earth days at a semi-major axis of 0.1014 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 87.2 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 724 K (+451°C / +844°F) and receiving 45.00 S⊕ (~61,245 W/m²), K2-65 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-65 is classified as a stellar host with an effective photospheric temperature of 5,213 K, a radius of 0.84 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.468 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.34 dex (metal-poor relative to the Sun). From Earth, K2-65 shines at apparent V-band magnitude 10.71 (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 | K2-65 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,213 K |
| Stellar Radius | 0.8400 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.468 L☉ |
| Metallicity [Fe/H] | -0.340 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 10.710 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.101400 AU |
| Orbital Period | 12.648 days |
| Mean Orbital Velocity | 87.2 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.1484° |
| Mean Bulk Density | 4.36 g/cm³ (15.7 km/s vesc) |
| Insolation Flux | 45.0000 S⊕ (~61,245 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 235.500 LY (72.200 pc) |