Kepler-176 e
Astrophysical Synthesis & Habitability Characterization
Kepler-176 e is a confirmed super-earth exoplanet orbiting the star Kepler-176, located approximately 1719.9 light-years (527.32 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0257% across the stellar disk), this world measures 1.45 Earth radii and has a measured mass of 0.521 Earth masses. Combining its mass and radius yields a mean bulk density of 0.94 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.25 g⊕ (2.45 m/s²), and an escape velocity of 6.7 km/s.
In its orbital architecture around Kepler-176, Kepler-176 e completes one full revolution every 51.166 Earth days at a semi-major axis of 0.25654 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 54.5 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 398 K (+125°C / +257°F) and receiving 6.22 S⊕ (~8,465 W/m²), Kepler-176 e orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-176 is classified as a stellar host with an effective photospheric temperature of 5,295 K, a radius of 0.83 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.486 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.68 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-176 shines at apparent V-band magnitude 14.767 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-176 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-176 e sharing its stellar neighborhood alongside Kepler-176 b, Kepler-176 c, Kepler-176 d.
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-176 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,295 K |
| Stellar Radius | 0.8300 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.486 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 4.680 Gyr |
| Apparent Magnitude | V: 14.767 · G: 14.545 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.256540 AU |
| Orbital Period | 51.166 days |
| Mean Orbital Velocity | 54.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.0800° |
| Mean Bulk Density | 0.94 g/cm³ (6.7 km/s vesc) |
| Insolation Flux | 6.2200 S⊕ (~8,465 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1719.900 LY (527.321 pc) |