Kepler-100 e
Astrophysical Synthesis & Habitability Characterization
Kepler-100 e is a confirmed sub-neptune exoplanet orbiting the star Kepler-100, located approximately 993.6 light-years (304.65 parsecs) from the Solar System. First announced in 2023 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 5.27 Earth radii (0.47 Jupiter radii) and has a measured mass of 24.143 Earth masses. Combining its mass and radius yields a mean bulk density of 0.91 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.87 g⊕ (8.53 m/s²), and an escape velocity of 23.9 km/s.
In its orbital architecture around Kepler-100, Kepler-100 e completes one full revolution every 60.889 Earth days at a semi-major axis of 0.312392 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 55.8 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.02644 (ranging from 0.3041 AU at periapsis to 0.3207 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 622 K (+349°C / +660°F) and receiving 25.41 S⊕ (~34,587 W/m²), Kepler-100 e orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-100 is classified as a stellar host with an effective photospheric temperature of 5,884 K, a radius of 1.5 R☉, a mass of 1.097 M☉, an estimated bolometric luminosity of 2.42 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.92 Gyr and a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, Kepler-100 shines at apparent V-band magnitude 11.055 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-100 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-100 e sharing its stellar neighborhood alongside Kepler-100 b, Kepler-100 c, Kepler-100 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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-100 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,884 K |
| Stellar Radius | 1.5000 R☉ |
| Stellar Mass | 1.0970 M☉ |
| Bolometric Luminosity | 2.42 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | 6.920 Gyr |
| Apparent Magnitude | V: 11.055 · G: 11.129 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.312392 AU |
| Orbital Period | 60.889 days |
| Mean Orbital Velocity | 55.8 km/s |
| Orbital Eccentricity (e) | 0.02644 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.91 g/cm³ (23.9 km/s vesc) |
| Insolation Flux | 25.4128 S⊕ (~34,587 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 993.600 LY (304.645 pc) |