K2-415 b
Astrophysical Synthesis & Habitability Characterization
K2-415 b is a confirmed terrestrial exoplanet orbiting the star K2-415, located approximately 71.2 light-years (21.82 parsecs) from the Solar System. First announced in 2023 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.2243% across the stellar disk), this world measures 1.015 Earth radii and has a measured mass of 7.5 Earth masses. Combining its mass and radius yields a mean bulk density of 39.55 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 7.28 g⊕ (71.39 m/s²), and an escape velocity of 30.4 km/s.
In its orbital architecture around K2-415, K2-415 b completes one full revolution every 4.018 Earth days at a semi-major axis of 0.027 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 73.1 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 412 K (+139°C / +282°F) and receiving 4.82 S⊕ (~6,560 W/m²), K2-415 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-415 is classified as a low-mass red dwarf of spectral type M5 V with an effective photospheric temperature of 3,173 K, a radius of 0.1965 R☉, a mass of 0.1635 M☉, an estimated bolometric luminosity of 0.00351 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.13 dex (metal-poor relative to the Sun). From Earth, K2-415 shines at apparent V-band magnitude 15.33 (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 | K2-415 |
| Spectral Type | M5 V |
| Effective Temp (Teff) | 3,173 K |
| Stellar Radius | 0.1965 R☉ |
| Stellar Mass | 0.1635 M☉ |
| Bolometric Luminosity | 0.00351 L☉ |
| Metallicity [Fe/H] | -0.130 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 15.330 · G: 13.796 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.027000 AU |
| Orbital Period | 4.018 days |
| Mean Orbital Velocity | 73.1 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.3200° |
| Mean Bulk Density | 39.55 g/cm³ (30.4 km/s vesc) |
| Insolation Flux | 4.8200 S⊕ (~6,560 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 71.200 LY (21.818 pc) |