Kepler-143 c
Astrophysical Synthesis & Habitability Characterization
Kepler-143 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-143, located approximately 2640.1 light-years (809.47 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0517% across the stellar disk), this world measures 3.37 Earth radii (0.3 Jupiter radii) and has a measured mass of 11.3 Earth masses. Combining its mass and radius yields a mean bulk density of 1.63 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.99 g⊕ (9.71 m/s²), and an escape velocity of 20.5 km/s.
In its orbital architecture around Kepler-143, Kepler-143 c completes one full revolution every 27.083 Earth days at a semi-major axis of 0.181 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 72.7 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 703 K (+430°C / +806°F) and receiving 58.70 S⊕ (~79,891 W/m²), Kepler-143 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-143 is classified as a stellar host with an effective photospheric temperature of 5,848 K, a radius of 1.359 R☉, a mass of 0.982 M☉, an estimated bolometric luminosity of 1.938 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.33 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-143 shines at apparent V-band magnitude 13.882 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-143 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-143 c sharing its stellar neighborhood alongside Kepler-143 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: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-143 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,848 K |
| Stellar Radius | 1.3590 R☉ |
| Stellar Mass | 0.9820 M☉ |
| Bolometric Luminosity | 1.938 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | 9.330 Gyr |
| Apparent Magnitude | V: 13.882 · G: 13.706 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.181000 AU |
| Orbital Period | 27.083 days |
| Mean Orbital Velocity | 72.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.2200° |
| Mean Bulk Density | 1.63 g/cm³ (20.5 km/s vesc) |
| Insolation Flux | 58.7000 S⊕ (~79,891 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2640.100 LY (809.467 pc) |