K2-416 b
Astrophysical Synthesis & Habitability Characterization
K2-416 b is a confirmed sub-neptune exoplanet orbiting the star K2-416, located approximately 392.4 light-years (120.31 parsecs) from the Solar System. First announced in 2023 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.1938% across the stellar disk), this world measures 2.66 Earth radii and has a measured mass of 1652.708 Earth masses (5.2 Jupiter masses). Combining its mass and radius yields a mean bulk density of 484.19 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 233.58 g⊕ (2290.64 m/s²), and an escape velocity of 278.8 km/s.
In its orbital architecture around K2-416, K2-416 b completes one full revolution every 13.102 Earth days at a semi-major axis of 0.088 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 73.1 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 447 K (+174°C / +345°F) and receiving 6.93 S⊕ (~9,438 W/m²), K2-416 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-416 is classified as a low-mass red dwarf of spectral type M V with an effective photospheric temperature of 3,746 K, a radius of 0.554 R☉, a mass of 0.548 M☉, an estimated bolometric luminosity of 0.054 L☉. From Earth, K2-416 shines at apparent V-band magnitude 14.794 (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 | K2-416 |
| Spectral Type | M V |
| Effective Temp (Teff) | 3,746 K |
| Stellar Radius | 0.5540 R☉ |
| Stellar Mass | 0.5480 M☉ |
| Bolometric Luminosity | 0.054 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 14.794 · G: 13.947 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.088000 AU |
| Orbital Period | 13.102 days |
| Mean Orbital Velocity | 73.1 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.2500° |
| Mean Bulk Density | 484.19 g/cm³ (278.8 km/s vesc) |
| Insolation Flux | 6.9344 S⊕ (~9,438 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 392.400 LY (120.311 pc) |