Kepler-333 c
Astrophysical Synthesis & Habitability Characterization
Kepler-333 c is a confirmed terrestrial exoplanet orbiting the star Kepler-333, located approximately 1058.1 light-years (324.41 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0363% across the stellar disk), this world measures 1.11 Earth radii and has a measured mass of 1.41 Earth masses. Combining its mass and radius yields a mean bulk density of 5.68 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.14 g⊕ (11.18 m/s²), and an escape velocity of 12.6 km/s.
In its orbital architecture around Kepler-333, Kepler-333 c completes one full revolution every 24.088 Earth days at a semi-major axis of 0.135 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 61 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 386 K (+113°C / +235°F) and receiving 7.05 S⊕ (~9,594 W/m²), Kepler-333 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-333 is classified as a stellar host with an effective photospheric temperature of 4,259 K, a radius of 0.534 R☉, a mass of 0.601 M☉, an estimated bolometric luminosity of 0.084 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.24 Gyr and a metallicity of [Fe/H] = 0.047 dex (near-solar heavy-element abundance). From Earth, Kepler-333 shines at apparent V-band magnitude 15.052 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-333 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-333 c sharing its stellar neighborhood alongside Kepler-333 b.
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-333 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,259 K |
| Stellar Radius | 0.5340 R☉ |
| Stellar Mass | 0.6010 M☉ |
| Bolometric Luminosity | 0.084 L☉ |
| Metallicity [Fe/H] | 0.047 dex |
| Stellar Age | 3.240 Gyr |
| Apparent Magnitude | V: 15.052 · G: 14.721 |
| System Architecture | 2 Stars, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.135000 AU |
| Orbital Period | 24.088 days |
| Mean Orbital Velocity | 61 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.5100° |
| Mean Bulk Density | 5.68 g/cm³ (12.6 km/s vesc) |
| Insolation Flux | 7.0490 S⊕ (~9,594 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1058.100 LY (324.413 pc) |