Kepler-124 b
Astrophysical Synthesis & Habitability Characterization
Kepler-124 b is a confirmed sub-earth exoplanet orbiting the star Kepler-124, located approximately 1370 light-years (420.05 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0111% across the stellar disk), this world measures 0.73 Earth radii and has a measured mass of 0.315 Earth masses. Combining its mass and radius yields a mean bulk density of 4.46 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.59 g⊕ (5.79 m/s²), and an escape velocity of 7.3 km/s.
In its orbital architecture around Kepler-124, Kepler-124 b completes one full revolution every 3.41 Earth days at a semi-major axis of 0.039 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 124.4 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 892 K (+619°C / +1146°F) and receiving 198.84 S⊕ (~270,625 W/m²), Kepler-124 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-124 is classified as a stellar host with an effective photospheric temperature of 4,984 K, a radius of 0.636 R☉, a mass of 0.706 M☉, an estimated bolometric luminosity of 0.224 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.82 Gyr and a metallicity of [Fe/H] = -0.46 dex (metal-poor relative to the Sun). From Earth, Kepler-124 shines at apparent V-band magnitude 14.4 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-124 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-124 b sharing its stellar neighborhood alongside Kepler-124 c, Kepler-124 d.
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-124 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,984 K |
| Stellar Radius | 0.6360 R☉ |
| Stellar Mass | 0.7060 M☉ |
| Bolometric Luminosity | 0.224 L☉ |
| Metallicity [Fe/H] | -0.460 dex |
| Stellar Age | 1.820 Gyr |
| Apparent Magnitude | V: 14.400 · G: 14.124 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.039000 AU |
| Orbital Period | 3.41 days |
| Mean Orbital Velocity | 124.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 70.0600° |
| Mean Bulk Density | 4.46 g/cm³ (7.3 km/s vesc) |
| Insolation Flux | 198.8430 S⊕ (~270,625 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1370.000 LY (420.046 pc) |