Kepler-674 b
Astrophysical Synthesis & Habitability Characterization
Kepler-674 b is a confirmed super-earth exoplanet orbiting the star Kepler-674, located approximately 1116.3 light-years (342.25 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0739% across the stellar disk), this world measures 1.69 Earth radii and has a measured mass of 3.5 Earth masses. Combining its mass and radius yields a mean bulk density of 4 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 16.1 km/s.
In its orbital architecture around Kepler-674, Kepler-674 b completes one full revolution every 2.243 Earth days at a semi-major axis of 0.028 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 135.8 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 822 K (+549°C / +1020°F) and receiving 146.51 S⊕ (~199,401 W/m²), Kepler-674 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-674 is classified as a stellar host with an effective photospheric temperature of 4,192 K, a radius of 0.57 R☉, a mass of 0.6 M☉, an estimated bolometric luminosity of 0.09 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.31 Gyr and a metallicity of [Fe/H] = -0.27 dex (metal-poor relative to the Sun). From Earth, Kepler-674 shines at apparent V-band magnitude 15.569 (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-674 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,192 K |
| Stellar Radius | 0.5700 R☉ |
| Stellar Mass | 0.6000 M☉ |
| Bolometric Luminosity | 0.09 L☉ |
| Metallicity [Fe/H] | -0.270 dex |
| Stellar Age | 3.310 Gyr |
| Apparent Magnitude | V: 15.569 · G: 15.127 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.028000 AU |
| Orbital Period | 2.243 days |
| Mean Orbital Velocity | 135.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 82.8800° |
| Mean Bulk Density | 4 g/cm³ (16.1 km/s vesc) |
| Insolation Flux | 146.5110 S⊕ (~199,401 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1116.300 LY (342.254 pc) |