Kepler-1931 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1931 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1931, located approximately 2022.5 light-years (620.09 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0397% across the stellar disk), this world measures 2.653 Earth radii and has a measured mass of 7.53 Earth masses. Combining its mass and radius yields a mean bulk density of 2.22 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.07 g⊕ (10.49 m/s²), and an escape velocity of 18.8 km/s.
In its orbital architecture around Kepler-1931, Kepler-1931 b completes one full revolution every 38.576 Earth days at a semi-major axis of 0.23329 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 65.8 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 619 K (+346°C / +655°F) and receiving 51.70 S⊕ (~70,364 W/m²), Kepler-1931 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1931 is classified as a stellar host with an effective photospheric temperature of 6,167 K, a radius of 1.221 R☉, a mass of 1.174 M☉, an estimated bolometric luminosity of 1.935 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.57 Gyr and a metallicity of [Fe/H] = 0.12 dex (metal-rich relative to the Sun). From Earth, Kepler-1931 shines at apparent V-band magnitude 12.671 (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-1931 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,167 K |
| Stellar Radius | 1.2210 R☉ |
| Stellar Mass | 1.1740 M☉ |
| Bolometric Luminosity | 1.935 L☉ |
| Metallicity [Fe/H] | 0.120 dex |
| Stellar Age | 4.570 Gyr |
| Apparent Magnitude | V: 12.671 · G: 12.559 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.233290 AU |
| Orbital Period | 38.576 days |
| Mean Orbital Velocity | 65.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9400° |
| Mean Bulk Density | 2.22 g/cm³ (18.8 km/s vesc) |
| Insolation Flux | 51.7000 S⊕ (~70,364 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2022.500 LY (620.091 pc) |