Kepler-252 b
Astrophysical Synthesis & Habitability Characterization
Kepler-252 b is a confirmed terrestrial exoplanet orbiting the star Kepler-252, located approximately 1237.5 light-years (379.42 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0422% across the stellar disk), this world measures 1.23 Earth radii and has a measured mass of 2.04 Earth masses. Combining its mass and radius yields a mean bulk density of 6.04 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.35 g⊕ (13.24 m/s²), and an escape velocity of 14.4 km/s.
In its orbital architecture around Kepler-252, Kepler-252 b completes one full revolution every 6.668 Earth days at a semi-major axis of 0.058 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 94.6 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 587 K (+314°C / +597°F) and receiving 39.26 S⊕ (~53,438 W/m²), Kepler-252 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-252 is classified as a low-mass red dwarf of spectral type M0 V with an effective photospheric temperature of 4,208 K, a radius of 0.549 R☉, a mass of 0.61 M☉, an estimated bolometric luminosity of 0.085 L☉. Stellar evolution modeling indicates an estimated stellar age of 13.9 Gyr and a metallicity of [Fe/H] = -0.13 dex (metal-poor relative to the Sun). From Earth, Kepler-252 shines at apparent V-band magnitude 15.406 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-252 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-252 b sharing its stellar neighborhood alongside Kepler-252 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-252 |
| Spectral Type | M0 V |
| Effective Temp (Teff) | 4,208 K |
| Stellar Radius | 0.5490 R☉ |
| Stellar Mass | 0.6100 M☉ |
| Bolometric Luminosity | 0.085 L☉ |
| Metallicity [Fe/H] | -0.130 dex |
| Stellar Age | 13.900 Gyr |
| Apparent Magnitude | V: 15.406 · G: 15.029 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.058000 AU |
| Orbital Period | 6.668 days |
| Mean Orbital Velocity | 94.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.2400° |
| Mean Bulk Density | 6.04 g/cm³ (14.4 km/s vesc) |
| Insolation Flux | 39.2640 S⊕ (~53,438 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1237.500 LY (379.424 pc) |