K2-413 c
Astrophysical Synthesis & Habitability Characterization
K2-413 c is a confirmed terrestrial exoplanet orbiting the star K2-413, located approximately 930.1 light-years (285.16 parsecs) from the Solar System. First announced in 2022 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0261% across the stellar disk), this world measures 1.233 Earth radii and has a measured mass of 2.05 Earth masses. Combining its mass and radius yields a mean bulk density of 6.03 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.35 g⊕ (13.24 m/s²), and an escape velocity of 14.4 km/s.
In its orbital architecture around K2-413, K2-413 c completes one full revolution every 5.33 Earth days at a semi-major axis of 0.0426 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 86.9 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 805 K (+532°C / +990°F) and receiving 69.53 S⊕ (~94,629 W/m²), K2-413 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-413 is classified as a stellar host with an effective photospheric temperature of 4,116 K, a radius of 0.7 R☉, a mass of 0.808 M☉, an estimated bolometric luminosity of 0.126 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.205 dex (metal-poor relative to the Sun). From Earth, K2-413 shines at apparent V-band magnitude 15.013 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The K2-413 system is a multi-planet architecture hosting 2 confirmed worlds, with K2-413 c sharing its stellar neighborhood alongside K2-413 b.
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 | K2-413 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,116 K |
| Stellar Radius | 0.7000 R☉ |
| Stellar Mass | 0.8080 M☉ |
| Bolometric Luminosity | 0.126 L☉ |
| Metallicity [Fe/H] | -0.205 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 15.013 · G: 14.577 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.042600 AU |
| Orbital Period | 5.33 days |
| Mean Orbital Velocity | 86.9 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.9985° |
| Mean Bulk Density | 6.03 g/cm³ (14.4 km/s vesc) |
| Insolation Flux | 69.5290 S⊕ (~94,629 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 930.100 LY (285.162 pc) |