Kepler-52 d
Astrophysical Synthesis & Habitability Characterization
Kepler-52 d is a confirmed super-earth exoplanet orbiting the star Kepler-52, located approximately 1048.7 light-years (321.54 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1034% across the stellar disk), this world measures 1.95 Earth radii and has a measured mass of 88.878 Earth masses (0.28 Jupiter masses). Combining its mass and radius yields a mean bulk density of 66.09 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 23.37 g⊕ (229.18 m/s²), and an escape velocity of 75.5 km/s.
In its orbital architecture around Kepler-52, Kepler-52 d completes one full revolution every 36.445 Earth days at a semi-major axis of 0.182 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 54.3 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.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for Kepler-52 d place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star Kepler-52 is classified as a low-mass red dwarf of spectral type M0 V with an effective photospheric temperature of 4,263 K, a radius of 0.556 R☉, a mass of 0.577 M☉, an estimated bolometric luminosity of 0.092 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.01 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-52 shines at apparent V-band magnitude 15.513 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-52 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-52 d sharing its stellar neighborhood alongside Kepler-52 b, Kepler-52 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-52 |
| Spectral Type | M0 V |
| Effective Temp (Teff) | 4,263 K |
| Stellar Radius | 0.5560 R☉ |
| Stellar Mass | 0.5770 M☉ |
| Bolometric Luminosity | 0.092 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 1.010 Gyr |
| Apparent Magnitude | V: 15.513 · G: 15.059 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.182000 AU |
| Orbital Period | 36.445 days |
| Mean Orbital Velocity | 54.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9800° |
| Mean Bulk Density | 66.09 g/cm³ (75.5 km/s vesc) |
| Insolation Flux | 2.9450 S⊕ (~4,008 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1048.700 LY (321.542 pc) |