Kepler-876 b
Astrophysical Synthesis & Habitability Characterization
Kepler-876 b is a confirmed super-earth exoplanet orbiting the star Kepler-876, located approximately 2677.5 light-years (820.91 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.029% across the stellar disk), this world measures 1.43 Earth radii and has a measured mass of 2.63 Earth masses. Combining its mass and radius yields a mean bulk density of 4.96 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.29 g⊕ (12.65 m/s²), and an escape velocity of 15.2 km/s.
In its orbital architecture around Kepler-876, Kepler-876 b completes one full revolution every 5.144 Earth days at a semi-major axis of 0.0549 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 116.1 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 923 K (+650°C / +1202°F) and receiving 152.75 S⊕ (~207,887 W/m²), Kepler-876 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-876 is classified as a stellar host with an effective photospheric temperature of 5,060 K, a radius of 0.77 R☉, a mass of 0.81 M☉, an estimated bolometric luminosity of 0.349 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.25 Gyr and a metallicity of [Fe/H] = -0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-876 shines at apparent V-band magnitude 15.647 (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-876 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,060 K |
| Stellar Radius | 0.7700 R☉ |
| Stellar Mass | 0.8100 M☉ |
| Bolometric Luminosity | 0.349 L☉ |
| Metallicity [Fe/H] | -0.030 dex |
| Stellar Age | 5.250 Gyr |
| Apparent Magnitude | V: 15.647 · G: 15.330 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.054900 AU |
| Orbital Period | 5.144 days |
| Mean Orbital Velocity | 116.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.8800° |
| Mean Bulk Density | 4.96 g/cm³ (15.2 km/s vesc) |
| Insolation Flux | 152.7460 S⊕ (~207,887 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2677.500 LY (820.913 pc) |