Kepler-939 b
Astrophysical Synthesis & Habitability Characterization
Kepler-939 b is a confirmed super-earth exoplanet orbiting the star Kepler-939, located approximately 6828.5 light-years (2093.62 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0356% across the stellar disk), this world measures 1.75 Earth radii and has a measured mass of 3.71 Earth masses. Combining its mass and radius yields a mean bulk density of 3.82 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.21 g⊕ (11.87 m/s²), and an escape velocity of 16.3 km/s.
In its orbital architecture around Kepler-939, Kepler-939 b completes one full revolution every 14.878 Earth days at a semi-major axis of 0.1153 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 84.3 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.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 692 K (+419°C / +786°F) and receiving 54.19 S⊕ (~73,753 W/m²), Kepler-939 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-939 is classified as a stellar host with an effective photospheric temperature of 5,471 K, a radius of 0.85 R☉, a mass of 0.88 M☉, an estimated bolometric luminosity of 0.581 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.47 Gyr and a metallicity of [Fe/H] = -0.12 dex (metal-poor relative to the Sun). From Earth, Kepler-939 shines at apparent V-band magnitude 15.653 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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-939 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,471 K |
| Stellar Radius | 0.8500 R☉ |
| Stellar Mass | 0.8800 M☉ |
| Bolometric Luminosity | 0.581 L☉ |
| Metallicity [Fe/H] | -0.120 dex |
| Stellar Age | 4.470 Gyr |
| Apparent Magnitude | V: 15.653 · G: 15.520 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.115300 AU |
| Orbital Period | 14.878 days |
| Mean Orbital Velocity | 84.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.9100° |
| Mean Bulk Density | 3.82 g/cm³ (16.3 km/s vesc) |
| Insolation Flux | 54.1900 S⊕ (~73,753 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 6828.500 LY (2093.620 pc) |