HD 102329 c
Astrophysical Synthesis & Habitability Characterization
HD 102329 c is a confirmed gas giant exoplanet orbiting the star HD 102329, located approximately 708.1 light-years (217.11 parsecs) from the Solar System. First announced in 2016 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.5 Earth radii (1.2 Jupiter radii) and has a measured mass of 483.102 Earth masses (1.52 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.08 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.65 g⊕ (25.99 m/s²), and an escape velocity of 66.9 km/s.
In its orbital architecture around HD 102329, HD 102329 c completes one full revolution every 1123 Earth days (3.07Julian years). Its moderate orbital eccentricity of e = 0.209 driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.500 R⊕, HD 102329 c exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star HD 102329 is classified as an orange K-type star of spectral type K0 III with an effective photospheric temperature of 4,830 K, a radius of 6.3 R☉, a mass of 1.3 M☉, an estimated bolometric luminosity of 19.38 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.6 Gyr and a metallicity of [Fe/H] = 0.3 dex (metal-rich relative to the Sun). From Earth, HD 102329 shines at apparent V-band magnitude 7.88 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 102329 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 102329 c sharing its stellar neighborhood alongside HD 102329 b.
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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 102329 |
| Spectral Type | K0 III |
| Effective Temp (Teff) | 4,830 K |
| Stellar Radius | 6.3000 R☉ |
| Stellar Mass | 1.3000 M☉ |
| Bolometric Luminosity | 19.38 L☉ |
| Metallicity [Fe/H] | 0.300 dex |
| Stellar Age | 1.600 Gyr |
| Apparent Magnitude | V: 7.880 · G: 7.582 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 1123 days |
| Orbital Eccentricity (e) | 0.20900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.08 g/cm³ (66.9 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 708.100 LY (217.107 pc) |