K2-244 b
Astrophysical Synthesis & Habitability Characterization
K2-244 b is a confirmed super-earth exoplanet orbiting the star K2-244, located approximately 694.4 light-years (212.9 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0304% across the stellar disk), this world measures 1.75 Earth radii and has a measured mass of 3.71 Earth masses. Combining its mass and radius yields a mean bulk density of 3.82 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.21 g⊕ (11.87 m/s²), and an escape velocity of 16.3 km/s.
In its orbital architecture around K2-244, K2-244 b completes one full revolution every 21.069 Earth days at a semi-major axis of 0.1418 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 73.2 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 638 K (+365°C / +689°F) and receiving 37.90 S⊕ (~51,583 W/m²), K2-244 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-244 is classified as a stellar host with an effective photospheric temperature of 5,677 K, a radius of 0.92 R☉, a mass of 0.86 M☉, an estimated bolometric luminosity of 0.789 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.29 dex (metal-poor relative to the Sun). From Earth, K2-244 shines at apparent V-band magnitude 11.78 (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 | K2-244 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,677 K |
| Stellar Radius | 0.9200 R☉ |
| Stellar Mass | 0.8600 M☉ |
| Bolometric Luminosity | 0.789 L☉ |
| Metallicity [Fe/H] | -0.290 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 11.780 · G: 11.632 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.141800 AU |
| Orbital Period | 21.069 days |
| Mean Orbital Velocity | 73.2 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.2139° |
| Mean Bulk Density | 3.82 g/cm³ (16.3 km/s vesc) |
| Insolation Flux | 37.9007 S⊕ (~51,583 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 694.400 LY (212.902 pc) |