Kepler-167 d
Astrophysical Synthesis & Habitability Characterization
Kepler-167 d is a confirmed terrestrial exoplanet orbiting the star Kepler-167, located approximately 1115.2 light-years (341.91 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.023% across the stellar disk), this world measures 1.238 Earth radii and has a measured mass of 2.06 Earth masses. Combining its mass and radius yields a mean bulk density of 5.99 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.34 g⊕ (13.14 m/s²), and an escape velocity of 14.4 km/s.
In its orbital architecture around Kepler-167, Kepler-167 d completes one full revolution every 21.804 Earth days at a semi-major axis of 0.1404 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 70.1 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 538 K (+265°C / +509°F) and receiving 14.49 S⊕ (~19,720 W/m²), Kepler-167 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-167 is classified as an orange K-type star of spectral type K4 with an effective photospheric temperature of 4,884 K, a radius of 0.749 R☉, a mass of 0.777 M☉, an estimated bolometric luminosity of 0.286 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.1 Gyr and a metallicity of [Fe/H] = 0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-167 shines at apparent V-band magnitude 14.284 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-167 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-167 d sharing its stellar neighborhood alongside Kepler-167 b, Kepler-167 c, Kepler-167 e.
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-167 |
| Spectral Type | K4 |
| Effective Temp (Teff) | 4,884 K |
| Stellar Radius | 0.7490 R☉ |
| Stellar Mass | 0.7770 M☉ |
| Bolometric Luminosity | 0.286 L☉ |
| Metallicity [Fe/H] | 0.020 dex |
| Stellar Age | 7.100 Gyr |
| Apparent Magnitude | V: 14.284 · G: 14.000 |
| System Architecture | 2 Stars, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.140400 AU |
| Orbital Period | 21.804 days |
| Mean Orbital Velocity | 70.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.2600° |
| Mean Bulk Density | 5.99 g/cm³ (14.4 km/s vesc) |
| Insolation Flux | 14.4890 S⊕ (~19,720 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1115.200 LY (341.908 pc) |