Kepler-327 d
Astrophysical Synthesis & Habitability Characterization
Kepler-327 d is a confirmed super-earth exoplanet orbiting the star Kepler-327, located approximately 789.3 light-years (241.99 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1039% across the stellar disk), this world measures 1.73 Earth radii and has a measured mass of 3.64 Earth masses. Combining its mass and radius yields a mean bulk density of 3.88 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 16.2 km/s.
In its orbital architecture around Kepler-327, Kepler-327 d completes one full revolution every 13.969 Earth days at a semi-major axis of 0.09 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 70.1 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 387 K (+114°C / +237°F) and receiving 7.59 S⊕ (~10,330 W/m²), Kepler-327 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-327 is classified as a stellar host with an effective photospheric temperature of 3,799 K, a radius of 0.492 R☉, a mass of 0.5919 M☉, an estimated bolometric luminosity of 0.045 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.28 Gyr and a metallicity of [Fe/H] = -0.2 dex (metal-poor relative to the Sun). From Earth, Kepler-327 shines at apparent V-band magnitude 15.611 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-327 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-327 d sharing its stellar neighborhood alongside Kepler-327 b, Kepler-327 c.
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-327 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,799 K |
| Stellar Radius | 0.4920 R☉ |
| Stellar Mass | 0.5919 M☉ |
| Bolometric Luminosity | 0.045 L☉ |
| Metallicity [Fe/H] | -0.200 dex |
| Stellar Age | 3.280 Gyr |
| Apparent Magnitude | V: 15.611 · G: 14.980 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.090000 AU |
| Orbital Period | 13.969 days |
| Mean Orbital Velocity | 70.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.5000° |
| Mean Bulk Density | 3.88 g/cm³ (16.2 km/s vesc) |
| Insolation Flux | 7.5900 S⊕ (~10,330 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 789.300 LY (241.987 pc) |