HD 219134 b
Astrophysical Synthesis & Habitability Characterization
HD 219134 b is a confirmed super-earth 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 1.602 Earth radii and has a measured mass of 4.74 Earth masses. Combining its mass and radius yields a mean bulk density of 6.36 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.85 g⊕ (18.14 m/s²), and an escape velocity of 19.2 km/s.
In its orbital architecture around HD 219134, HD 219134 b completes one full revolution every 3.093 Earth days at a semi-major axis of 0.03876 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 136.3 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 1015 K (+742°C / +1368°F) and receiving 176.20 S⊕ (~239,808 W/m²), HD 219134 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 219134 is classified as an orange K-type star of spectral type K3 V with an effective photospheric temperature of 4,699 K, a radius of 0.778 R☉, a mass of 0.81 M☉, an estimated bolometric luminosity of 0.265 L☉. Stellar evolution modeling indicates an estimated stellar age of 11 Gyr and a metallicity of [Fe/H] = 0.11 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 b sharing its stellar neighborhood alongside HD 219134 c, HD 219134 f, HD 219134 d, HD 219134 g, HD 219134 h.
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) | 4,699 K |
| Stellar Radius | 0.7780 R☉ |
| Stellar Mass | 0.8100 M☉ |
| Bolometric Luminosity | 0.265 L☉ |
| Metallicity [Fe/H] | 0.110 dex |
| Stellar Age | 11.000 Gyr |
| Apparent Magnitude | V: 5.569 · G: 5.240 |
| System Architecture | 1 Star, 6 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.038760 AU |
| Orbital Period | 3.093 days |
| Mean Orbital Velocity | 136.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.0500° |
| Mean Bulk Density | 6.36 g/cm³ (19.2 km/s vesc) |
| Insolation Flux | 176.2000 S⊕ (~239,808 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 21.300 LY (6.531 pc) |