Kepler-520 c
Astrophysical Synthesis & Habitability Characterization
Kepler-520 c is a confirmed terrestrial exoplanet orbiting the star Kepler-520, located approximately 2034.9 light-years (623.9 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 1.07 Earth radii and has a measured mass of 1.24 Earth masses. Combining its mass and radius yields a mean bulk density of 5.58 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.08 g⊕ (10.59 m/s²), and an escape velocity of 12 km/s.
In its orbital architecture around Kepler-520, Kepler-520 c completes one full revolution every 5.211 Earth days at a semi-major axis of 0.06035 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 126 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 1107 K (+834°C / +1533°F) and receiving 351.69 S⊕ (~478,650 W/m²), Kepler-520 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-520 is classified as a stellar host with an effective photospheric temperature of 6,112 K, a radius of 1.09 R☉, a mass of 1.1 M☉, an estimated bolometric luminosity of 1.488 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.04 Gyr and a metallicity of [Fe/H] = -0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-520 shines at apparent V-band magnitude 12.798 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-520 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-520 c sharing its stellar neighborhood alongside Kepler-520 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-520 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,112 K |
| Stellar Radius | 1.0900 R☉ |
| Stellar Mass | 1.1000 M☉ |
| Bolometric Luminosity | 1.488 L☉ |
| Metallicity [Fe/H] | -0.030 dex |
| Stellar Age | 2.040 Gyr |
| Apparent Magnitude | V: 12.798 · G: 12.760 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.060350 AU |
| Orbital Period | 5.211 days |
| Mean Orbital Velocity | 126 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 83.0200° |
| Mean Bulk Density | 5.58 g/cm³ (12 km/s vesc) |
| Insolation Flux | 351.6900 S⊕ (~478,650 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2034.900 LY (623.901 pc) |