Kepler-501 b
Astrophysical Synthesis & Habitability Characterization
Kepler-501 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-501, located approximately 3670 light-years (1125.24 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1437% across the stellar disk), this world measures 4.3 Earth radii (0.38 Jupiter radii) and has a measured mass of 17.1 Earth masses. Combining its mass and radius yields a mean bulk density of 1.19 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.92 g⊕ (9.02 m/s²), and an escape velocity of 22.3 km/s.
In its orbital architecture around Kepler-501, Kepler-501 b completes one full revolution every 5.641 Earth days at a semi-major axis of 0.0627 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 120.9 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 1125 K (+852°C / +1566°F) and receiving 324.86 S⊕ (~442,129 W/m²), Kepler-501 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-501 is classified as a stellar host with an effective photospheric temperature of 5,904 K, a radius of 1.04 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.179 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.31 Gyr and a metallicity of [Fe/H] = -0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-501 shines at apparent V-band magnitude 14.886 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-501 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-501 b sharing its stellar neighborhood alongside Kepler-501 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-501 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,904 K |
| Stellar Radius | 1.0400 R☉ |
| Stellar Mass | 1.0300 M☉ |
| Bolometric Luminosity | 1.179 L☉ |
| Metallicity [Fe/H] | -0.030 dex |
| Stellar Age | 3.310 Gyr |
| Apparent Magnitude | V: 14.886 · G: 14.730 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.062700 AU |
| Orbital Period | 5.641 days |
| Mean Orbital Velocity | 120.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.8800° |
| Mean Bulk Density | 1.19 g/cm³ (22.3 km/s vesc) |
| Insolation Flux | 324.8560 S⊕ (~442,129 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3670.000 LY (1125.240 pc) |