K2-319 b
Astrophysical Synthesis & Habitability Characterization
K2-319 b is a confirmed sub-neptune exoplanet orbiting the star K2-319, located approximately 681.9 light-years (209.07 parsecs) from the Solar System. First announced in 2020 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0811% across the stellar disk), this world measures 2.79 Earth radii and has a measured mass of 8.2 Earth masses. Combining its mass and radius yields a mean bulk density of 2.08 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.05 g⊕ (10.3 m/s²), and an escape velocity of 19.2 km/s.
In its orbital architecture around K2-319, K2-319 b completes one full revolution every 26.68 Earth days at a semi-major axis of 0.1516 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 61.8 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 641 K (+368°C / +694°F) and receiving 25.18 S⊕ (~34,276 W/m²), K2-319 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-319 is classified as a stellar host with an effective photospheric temperature of 5,440 K, a radius of 0.898 R☉, a mass of 0.954 M☉, an estimated bolometric luminosity of 0.634 L☉. From Earth, K2-319 shines at apparent V-band magnitude 12.213 (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 | K2-319 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,440 K |
| Stellar Radius | 0.8980 R☉ |
| Stellar Mass | 0.9540 M☉ |
| Bolometric Luminosity | 0.634 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 12.213 · G: 11.940 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.151600 AU |
| Orbital Period | 26.68 days |
| Mean Orbital Velocity | 61.8 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.4500° |
| Mean Bulk Density | 2.08 g/cm³ (19.2 km/s vesc) |
| Insolation Flux | 25.1842 S⊕ (~34,276 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 681.900 LY (209.071 pc) |