Kepler-564 b
Astrophysical Synthesis & Habitability Characterization
Kepler-564 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-564, located approximately 2814.8 light-years (863.04 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.2129% across the stellar disk), this world measures 4.63 Earth radii (0.41 Jupiter radii) and has a measured mass of 19.4 Earth masses. Combining its mass and radius yields a mean bulk density of 1.08 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.9 g⊕ (8.83 m/s²), and an escape velocity of 22.9 km/s.
In its orbital architecture around Kepler-564, Kepler-564 b completes one full revolution every 3.751 Earth days at a semi-major axis of 0.0484 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 140.4 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 1129 K (+856°C / +1573°F) and receiving 389.40 S⊕ (~529,979 W/m²), Kepler-564 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-564 is classified as a stellar host with an effective photospheric temperature of 5,626 K, a radius of 0.92 R☉, a mass of 0.95 M☉, an estimated bolometric luminosity of 0.761 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-564 shines at apparent V-band magnitude 14.883 (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-564 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,626 K |
| Stellar Radius | 0.9200 R☉ |
| Stellar Mass | 0.9500 M☉ |
| Bolometric Luminosity | 0.761 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | 4.270 Gyr |
| Apparent Magnitude | V: 14.883 · G: 14.719 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.048400 AU |
| Orbital Period | 3.751 days |
| Mean Orbital Velocity | 140.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 1.08 g/cm³ (22.9 km/s vesc) |
| Insolation Flux | 389.4040 S⊕ (~529,979 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2814.800 LY (863.037 pc) |