Kepler-874 b
Astrophysical Synthesis & Habitability Characterization
Kepler-874 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-874, located approximately 3529.5 light-years (1082.16 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1022% across the stellar disk), this world measures 3.94 Earth radii (0.35 Jupiter radii) and has a measured mass of 14.7 Earth masses. Combining its mass and radius yields a mean bulk density of 1.33 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.95 g⊕ (9.32 m/s²), and an escape velocity of 21.6 km/s.
In its orbital architecture around Kepler-874, Kepler-874 b completes one full revolution every 40.069 Earth days at a semi-major axis of 0.2234 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 60.7 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 560 K (+287°C / +549°F) and receiving 31.62 S⊕ (~43,040 W/m²), Kepler-874 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-874 is classified as a stellar host with an effective photospheric temperature of 6,020 K, a radius of 1.13 R☉, a mass of 1.09 M☉, an estimated bolometric luminosity of 1.505 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-874 shines at apparent V-band magnitude 14.822 (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-874 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,020 K |
| Stellar Radius | 1.1300 R☉ |
| Stellar Mass | 1.0900 M☉ |
| Bolometric Luminosity | 1.505 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 3.310 Gyr |
| Apparent Magnitude | V: 14.822 · G: 14.694 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.223400 AU |
| Orbital Period | 40.069 days |
| Mean Orbital Velocity | 60.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9700° |
| Mean Bulk Density | 1.33 g/cm³ (21.6 km/s vesc) |
| Insolation Flux | 31.6240 S⊕ (~43,040 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3529.500 LY (1082.160 pc) |