Kepler-1651 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1651 b is a confirmed super-earth exoplanet orbiting the star Kepler-1651, located approximately 216.6 light-years (66.41 parsecs) from the Solar System. First announced in 2017 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1125% across the stellar disk), this world measures 1.84 Earth radii and has a measured mass of 4.04 Earth masses. Combining its mass and radius yields a mean bulk density of 3.58 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 16.6 km/s.
In its orbital architecture around Kepler-1651, Kepler-1651 b completes one full revolution every 9.879 Earth days at a semi-major axis of 0.0692 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 76.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.13 carries the world between 0.0602 AU at periapsis and 0.0782 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 393 K (+120°C / +248°F) and receiving 5.65 S⊕ (~7,690 W/m²), Kepler-1651 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1651 is classified as a stellar host with an effective photospheric temperature of 3,713 K, a radius of 0.503 R☉, a mass of 0.522 M☉, an estimated bolometric luminosity of 0.043 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.16 dex (metal-poor relative to the Sun). From Earth, Kepler-1651 shines at apparent V-band magnitude 13.86 (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-1651 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,713 K |
| Stellar Radius | 0.5030 R☉ |
| Stellar Mass | 0.5220 M☉ |
| Bolometric Luminosity | 0.043 L☉ |
| Metallicity [Fe/H] | -0.160 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 13.860 · G: 13.072 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.069200 AU |
| Orbital Period | 9.879 days |
| Mean Orbital Velocity | 76.2 km/s |
| Orbital Eccentricity (e) | 0.13000 |
| Orbital Inclination (i) | 89.9700° |
| Mean Bulk Density | 3.58 g/cm³ (16.6 km/s vesc) |
| Insolation Flux | 5.6500 S⊕ (~7,690 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 216.600 LY (66.407 pc) |