Kepler-191 c
Astrophysical Synthesis & Habitability Characterization
Kepler-191 c is a confirmed super-earth exoplanet orbiting the star Kepler-191, located approximately 1938.9 light-years (594.46 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0467% 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-191, Kepler-191 c completes one full revolution every 17.739 Earth days at a semi-major axis of 0.128 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 78.5 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 596 K (+323°C / +613°F) and receiving 23.20 S⊕ (~31,575 W/m²), Kepler-191 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-191 is classified as a stellar host with an effective photospheric temperature of 5,282 K, a radius of 0.789 R☉, a mass of 0.857 M☉, an estimated bolometric luminosity of 0.435 L☉. Stellar evolution modeling indicates an estimated stellar age of 1 Gyr and a metallicity of [Fe/H] = 0.13 dex (metal-rich relative to the Sun). From Earth, Kepler-191 shines at apparent V-band magnitude 14.987 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-191 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-191 c sharing its stellar neighborhood alongside Kepler-191 d, Kepler-191 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-191 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,282 K |
| Stellar Radius | 0.7890 R☉ |
| Stellar Mass | 0.8570 M☉ |
| Bolometric Luminosity | 0.435 L☉ |
| Metallicity [Fe/H] | 0.130 dex |
| Stellar Age | 1.000 Gyr |
| Apparent Magnitude | V: 14.987 · G: 14.776 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.128000 AU |
| Orbital Period | 17.739 days |
| Mean Orbital Velocity | 78.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.1600° |
| Mean Bulk Density | 3.53 g/cm³ (16.6 km/s vesc) |
| Insolation Flux | 23.2000 S⊕ (~31,575 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1938.900 LY (594.464 pc) |