HD 219134 h
Astrophysical Synthesis & Habitability Characterization
HD 219134 h is a confirmed gas giant exoplanet orbiting the star HD 219134, located approximately 21.3 light-years (6.53 parsecs) from the Solar System. First announced in 2015 by Roque de los Muchachos Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.7 Earth radii (1.13 Jupiter radii) and has a measured mass of 108.062 Earth masses (0.34 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.29 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.67 g⊕ (6.57 m/s²), and an escape velocity of 32.6 km/s.
In its orbital architecture around HD 219134, HD 219134 h completes one full revolution every 2247 Earth days (6.15Julian years) at a semi-major axis of 3.11 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 15.1 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.06 carries the world between 2.9234 AU at periapsis and 3.2966 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 118 K (-155°C / -247°F) and an incident flux of 0.03 S⊕ (~44 W/m²), surface water and volatile species on HD 219134 h would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 219134 is classified as an orange K-type star of spectral type K3 V with an effective photospheric temperature of 4,913 K, a radius of 0.77 R☉, a mass of 0.794 M☉, an estimated bolometric luminosity of 0.31 L☉. Stellar evolution modeling indicates an estimated stellar age of 12.46 Gyr and a metallicity of [Fe/H] = 0.08 dex (metal-rich relative to the Sun). From Earth, HD 219134 shines at apparent V-band magnitude 5.569 (visible to the unaided human eye under dark skies) in the Northern celestial hemisphere. The HD 219134 system is a multi-planet architecture hosting 6 confirmed worlds, with HD 219134 h sharing its stellar neighborhood alongside HD 219134 b, HD 219134 c, HD 219134 f, HD 219134 d, HD 219134 g.
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: Roque de los Muchachos Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 219134 |
| Spectral Type | K3 V |
| Effective Temp (Teff) | 4,913 K |
| Stellar Radius | 0.7700 R☉ |
| Stellar Mass | 0.7940 M☉ |
| Bolometric Luminosity | 0.31 L☉ |
| Metallicity [Fe/H] | 0.080 dex |
| Stellar Age | 12.460 Gyr |
| Apparent Magnitude | V: 5.569 · G: 5.240 |
| System Architecture | 1 Star, 6 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 3.110000 AU |
| Orbital Period | 2247 days |
| Mean Orbital Velocity | 15.1 km/s |
| Orbital Eccentricity (e) | 0.06000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.29 g/cm³ (32.6 km/s vesc) |
| Insolation Flux | 0.0321 S⊕ (~44 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 21.300 LY (6.531 pc) |