Kepler-79 d
Astrophysical Synthesis & Habitability Characterization
Kepler-79 d is a confirmed gas giant exoplanet orbiting the star Kepler-79, located approximately 3329.1 light-years (1020.72 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.2481% across the stellar disk), this world measures 7.15 Earth radii (0.64 Jupiter radii) and has a measured mass of 5.3 Earth masses. Combining its mass and radius yields a mean bulk density of 0.08 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.1 g⊕ (0.98 m/s²), and an escape velocity of 9.6 km/s.
In its orbital architecture around Kepler-79, Kepler-79 d completes one full revolution every 52.09 Earth days at a semi-major axis of 0.2937 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 61.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.051 carries the world between 0.2787 AU at periapsis and 0.3087 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 592 K (+319°C / +606°F) and receiving 33.87 S⊕ (~46,103 W/m²), Kepler-79 d orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-79 is classified as a stellar host with an effective photospheric temperature of 6,389 K, a radius of 1.316 R☉, a mass of 1.244 M☉, an estimated bolometric luminosity of 2.589 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.32 Gyr and a metallicity of [Fe/H] = 0.06 dex (metal-rich relative to the Sun). From Earth, Kepler-79 shines at apparent V-band magnitude 14.036 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-79 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-79 d sharing its stellar neighborhood alongside Kepler-79 b, Kepler-79 c, Kepler-79 e.
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-79 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,389 K |
| Stellar Radius | 1.3160 R☉ |
| Stellar Mass | 1.2440 M☉ |
| Bolometric Luminosity | 2.589 L☉ |
| Metallicity [Fe/H] | 0.060 dex |
| Stellar Age | 1.320 Gyr |
| Apparent Magnitude | V: 14.036 · G: 13.883 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.293700 AU |
| Orbital Period | 52.09 days |
| Mean Orbital Velocity | 61.3 km/s |
| Orbital Eccentricity (e) | 0.05100 |
| Orbital Inclination (i) | 89.8100° |
| Mean Bulk Density | 0.08 g/cm³ (9.6 km/s vesc) |
| Insolation Flux | 33.8740 S⊕ (~46,103 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3329.100 LY (1020.720 pc) |