Kepler-440 b
Astrophysical Synthesis & Habitability Characterization
Kepler-440 b is a confirmed super-earth exoplanet orbiting the star Kepler-440, located approximately 981.8 light-years (301.03 parsecs) from the Solar System. First announced in 2015 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0931% across the stellar disk), this world measures 1.86 Earth radii and has a measured mass of 4.12 Earth masses. Combining its mass and radius yields a mean bulk density of 3.53 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 16.6 km/s.
In its orbital architecture around Kepler-440, Kepler-440 b completes one full revolution every 101.111 Earth days at a semi-major axis of 0.242 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 26 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.34, swinging from 0.1597 AU at periapsis out to 0.3243 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 229 K (-44°C / -47°F) and an incident stellar irradiance of 1.20 S⊕ (~1,633 W/m²), Kepler-440 b orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star Kepler-440 is classified as a stellar host with an effective photospheric temperature of 4,134 K, a radius of 0.559 R☉, a mass of 0.575 M☉, an estimated bolometric luminosity of 0.082 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.3 Gyr and a metallicity of [Fe/H] = -0.3 dex (metal-poor relative to the Sun). From Earth, Kepler-440 shines at apparent V-band magnitude 15.637 (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: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-440 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,134 K |
| Stellar Radius | 0.5590 R☉ |
| Stellar Mass | 0.5750 M☉ |
| Bolometric Luminosity | 0.082 L☉ |
| Metallicity [Fe/H] | -0.300 dex |
| Stellar Age | 1.300 Gyr |
| Apparent Magnitude | V: 15.637 · G: 15.106 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.242000 AU |
| Orbital Period | 101.111 days |
| Mean Orbital Velocity | 26 km/s |
| Orbital Eccentricity (e) | 0.34000 |
| Orbital Inclination (i) | 89.9300° |
| Mean Bulk Density | 3.53 g/cm³ (16.6 km/s vesc) |
| Insolation Flux | 1.2000 S⊕ (~1,633 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 981.800 LY (301.030 pc) |