Kepler-1438 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1438 b is a confirmed terrestrial exoplanet orbiting the star Kepler-1438, located approximately 3764.3 light-years (1154.13 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0081% across the stellar disk), this world measures 0.94 Earth radii and has a measured mass of 0.779 Earth masses. Combining its mass and radius yields a mean bulk density of 5.17 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.88 g⊕ (8.63 m/s²), and an escape velocity of 10.2 km/s.
In its orbital architecture around Kepler-1438, Kepler-1438 b completes one full revolution every 2.319 Earth days at a semi-major axis of 0.0346 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 162.3 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1490 K (+1217°C / +2223°F) and receiving 561.12 S⊕ (~763,684 W/m²), Kepler-1438 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1438 is classified as a stellar host with an effective photospheric temperature of 5,530 K, a radius of 0.96 R☉, a mass of 0.97 M☉, an estimated bolometric luminosity of 0.773 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.37 Gyr and a metallicity of [Fe/H] = 0.2 dex (metal-rich relative to the Sun). From Earth, Kepler-1438 shines at apparent V-band magnitude 14.983 (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-1438 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,530 K |
| Stellar Radius | 0.9600 R☉ |
| Stellar Mass | 0.9700 M☉ |
| Bolometric Luminosity | 0.773 L☉ |
| Metallicity [Fe/H] | 0.200 dex |
| Stellar Age | 5.370 Gyr |
| Apparent Magnitude | V: 14.983 · G: 14.861 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.034600 AU |
| Orbital Period | 2.319 days |
| Mean Orbital Velocity | 162.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.5900° |
| Mean Bulk Density | 5.17 g/cm³ (10.2 km/s vesc) |
| Insolation Flux | 561.1200 S⊕ (~763,684 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3764.300 LY (1154.130 pc) |