Kepler-24 c
Astrophysical Synthesis & Habitability Characterization
Kepler-24 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-24, located approximately 3773 light-years (1156.81 parsecs) from the Solar System. First announced in 2011 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.044% across the stellar disk), this world measures 2.514 Earth radii and has a measured mass of 9.99 Earth masses. Combining its mass and radius yields a mean bulk density of 3.47 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.58 g⊕ (15.49 m/s²), and an escape velocity of 22.3 km/s.
In its orbital architecture around Kepler-24, Kepler-24 c completes one full revolution every 12.33 Earth days at a semi-major axis of 0.10612 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 93.6 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.014 (ranging from 0.1046 AU at periapsis to 0.1076 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 915 K (+642°C / +1188°F) and receiving 144.83 S⊕ (~197,110 W/m²), Kepler-24 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-24 is classified as a stellar host with an effective photospheric temperature of 6,028 K, a radius of 1.099 R☉, a mass of 1.06 M☉, an estimated bolometric luminosity of 1.431 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.02 Gyr and a metallicity of [Fe/H] = -0.071 dex (near-solar heavy-element abundance). From Earth, Kepler-24 shines at apparent V-band magnitude 15.04 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-24 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-24 c sharing its stellar neighborhood alongside Kepler-24 d, Kepler-24 b, Kepler-24 e.
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-24 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,028 K |
| Stellar Radius | 1.0990 R☉ |
| Stellar Mass | 1.0600 M☉ |
| Bolometric Luminosity | 1.431 L☉ |
| Metallicity [Fe/H] | -0.071 dex |
| Stellar Age | 3.020 Gyr |
| Apparent Magnitude | V: 15.040 · G: 14.923 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.106120 AU |
| Orbital Period | 12.33 days |
| Mean Orbital Velocity | 93.6 km/s |
| Orbital Eccentricity (e) | 0.01400 |
| Orbital Inclination (i) | 78.6300° |
| Mean Bulk Density | 3.47 g/cm³ (22.3 km/s vesc) |
| Insolation Flux | 144.8270 S⊕ (~197,110 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3773.000 LY (1156.810 pc) |