Kepler-83 c
Astrophysical Synthesis & Habitability Characterization
Kepler-83 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-83, located approximately 1306 light-years (400.41 parsecs) from the Solar System. First announced in 2012 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1258% across the stellar disk), this world measures 2.36 Earth radii and has a measured mass of 2.03 Earth masses. Combining its mass and radius yields a mean bulk density of 0.85 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.36 g⊕ (3.53 m/s²), and an escape velocity of 10.4 km/s.
In its orbital architecture around Kepler-83, Kepler-83 c completes one full revolution every 20.09 Earth days at a semi-major axis of 0.11796 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 63.9 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 362 K (+89°C / +192°F) and receiving 5.90 S⊕ (~8,030 W/m²), Kepler-83 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-83 is classified as a low-mass red dwarf of spectral type M0 V with an effective photospheric temperature of 4,082 K, a radius of 0.61 R☉, a mass of 0.66 M☉, an estimated bolometric luminosity of 0.093 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.09 Gyr and a metallicity of [Fe/H] = -0.2 dex (metal-poor relative to the Sun). From Earth, Kepler-83 shines at apparent V-band magnitude 16.145 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-83 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-83 c sharing its stellar neighborhood alongside Kepler-83 d, Kepler-83 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-83 |
| Spectral Type | M0 V |
| Effective Temp (Teff) | 4,082 K |
| Stellar Radius | 0.6100 R☉ |
| Stellar Mass | 0.6600 M☉ |
| Bolometric Luminosity | 0.093 L☉ |
| Metallicity [Fe/H] | -0.200 dex |
| Stellar Age | 3.090 Gyr |
| Apparent Magnitude | V: 16.145 · G: 15.783 |
| System Architecture | 2 Stars, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.117960 AU |
| Orbital Period | 20.09 days |
| Mean Orbital Velocity | 63.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.4900° |
| Mean Bulk Density | 0.85 g/cm³ (10.4 km/s vesc) |
| Insolation Flux | 5.9000 S⊕ (~8,030 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1306.000 LY (400.409 pc) |