Kepler-51 e
Astrophysical Synthesis & Habitability Characterization
Kepler-51 e is a confirmed sub-neptune exoplanet orbiting the star Kepler-51, located approximately 2556.5 light-years (783.83 parsecs) from the Solar System. First announced in 2024 by Multiple Observatories using the Transit Timing Variations detection technique (producing an estimated primary transit depth of 0.0528% across the stellar disk), this world measures 2.18 Earth radii and has a measured mass of 5.4 Earth masses. Combining its mass and radius yields a mean bulk density of 2.87 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.14 g⊕ (11.18 m/s²), and an escape velocity of 17.6 km/s.
In its orbital architecture around Kepler-51, Kepler-51 e completes one full revolution every 264.284 Earth days. With a near-circular eccentricity of e = 0.02, the planet experiences minimal orbital distance variation.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for Kepler-51 e place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star Kepler-51 is classified as a stellar host with an effective photospheric temperature of 5,674 K, a radius of 0.87 R☉, a mass of 0.96 M☉, an estimated bolometric luminosity of 0.704 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.7 Gyr and a metallicity of [Fe/H] = 0.047 dex (near-solar heavy-element abundance). From Earth, Kepler-51 shines at apparent V-band magnitude 14.885 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-51 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-51 e sharing its stellar neighborhood alongside Kepler-51 b, Kepler-51 c, Kepler-51 d.
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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-51 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,674 K |
| Stellar Radius | 0.8700 R☉ |
| Stellar Mass | 0.9600 M☉ |
| Bolometric Luminosity | 0.704 L☉ |
| Metallicity [Fe/H] | 0.047 dex |
| Stellar Age | 0.700 Gyr |
| Apparent Magnitude | V: 14.885 · G: 14.678 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 264.284 days |
| Orbital Eccentricity (e) | 0.02000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.87 g/cm³ (17.6 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2556.500 LY (783.831 pc) |