Kepler-513 b
Astrophysical Synthesis & Habitability Characterization
Kepler-513 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-513, located approximately 1527.3 light-years (468.26 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0362% across the stellar disk), this world measures 2.2 Earth radii and has a measured mass of 5.48 Earth masses. Combining its mass and radius yields a mean bulk density of 2.84 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.13 g⊕ (11.08 m/s²), and an escape velocity of 17.7 km/s.
In its orbital architecture around Kepler-513, Kepler-513 b completes one full revolution every 28.862 Earth days at a semi-major axis of 0.1779 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 67.1 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 623 K (+350°C / +662°F) and receiving 36.53 S⊕ (~49,713 W/m²), Kepler-513 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-513 is classified as a stellar host with an effective photospheric temperature of 5,849 K, a radius of 1.06 R☉, a mass of 1.02 M☉, an estimated bolometric luminosity of 1.18 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.5 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-513 shines at apparent V-band magnitude 13.019 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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-513 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,849 K |
| Stellar Radius | 1.0600 R☉ |
| Stellar Mass | 1.0200 M☉ |
| Bolometric Luminosity | 1.18 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | 5.500 Gyr |
| Apparent Magnitude | V: 13.019 · G: 12.882 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.177900 AU |
| Orbital Period | 28.862 days |
| Mean Orbital Velocity | 67.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.3500° |
| Mean Bulk Density | 2.84 g/cm³ (17.7 km/s vesc) |
| Insolation Flux | 36.5270 S⊕ (~49,713 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1527.300 LY (468.258 pc) |