Kepler-650 b
Astrophysical Synthesis & Habitability Characterization
Kepler-650 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-650, located approximately 2884.5 light-years (884.38 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0404% across the stellar disk), this world measures 2.96 Earth radii and has a measured mass of 9.06 Earth masses. Combining its mass and radius yields a mean bulk density of 1.93 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.03 g⊕ (10.1 m/s²), and an escape velocity of 19.6 km/s.
In its orbital architecture around Kepler-650, Kepler-650 b completes one full revolution every 3.032 Earth days at a semi-major axis of 0.0421 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 151.1 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 1507 K (+1234°C / +2253°F) and receiving 1,218.88 S⊕ (~1,658,896 W/m²), Kepler-650 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-650 is classified as a stellar host with an effective photospheric temperature of 5,849 K, a radius of 1.35 R☉, a mass of 1.08 M☉, an estimated bolometric luminosity of 1.914 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.46 Gyr and a metallicity of [Fe/H] = 0.13 dex (metal-rich relative to the Sun). From Earth, Kepler-650 shines at apparent V-band magnitude 13.825 (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-650 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,849 K |
| Stellar Radius | 1.3500 R☉ |
| Stellar Mass | 1.0800 M☉ |
| Bolometric Luminosity | 1.914 L☉ |
| Metallicity [Fe/H] | 0.130 dex |
| Stellar Age | 6.460 Gyr |
| Apparent Magnitude | V: 13.825 · G: 14.124 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.042100 AU |
| Orbital Period | 3.032 days |
| Mean Orbital Velocity | 151.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 76.7700° |
| Mean Bulk Density | 1.93 g/cm³ (19.6 km/s vesc) |
| Insolation Flux | 1218.8800 S⊕ (~1,658,896 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2884.500 LY (884.378 pc) |