HD 148164 c
Astrophysical Synthesis & Habitability Characterization
HD 148164 c is a confirmed gas giant exoplanet orbiting the star HD 148164, located approximately 251.8 light-years (77.2 parsecs) from the Solar System. First announced in 2018 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 12.8 Earth radii (1.14 Jupiter radii) and has a measured mass of 1640.003 Earth masses (5.16 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.31 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 10.01 g⊕ (98.16 m/s²), and an escape velocity of 126.6 km/s.
In its orbital architecture around HD 148164, HD 148164 c completes one full revolution every 5062 Earth days (13.86Julian years) at a semi-major axis of 6.15 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 13.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.125 carries the world between 5.3813 AU at periapsis and 6.9188 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 136 K (-137°C / -215°F) and an incident flux of 0.06 S⊕ (~77 W/m²), surface water and volatile species on HD 148164 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 148164 is classified as a warm F-type star of spectral type F8 with an effective photospheric temperature of 6,032 K, a radius of 1.34 R☉, a mass of 1.21 M☉, an estimated bolometric luminosity of 2.133 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.41 Gyr and a metallicity of [Fe/H] = 0.24 dex (metal-rich relative to the Sun). From Earth, HD 148164 shines at apparent V-band magnitude 8.23 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 148164 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 148164 c sharing its stellar neighborhood alongside HD 148164 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 148164 |
| Spectral Type | F8 |
| Effective Temp (Teff) | 6,032 K |
| Stellar Radius | 1.3400 R☉ |
| Stellar Mass | 1.2100 M☉ |
| Bolometric Luminosity | 2.133 L☉ |
| Metallicity [Fe/H] | 0.240 dex |
| Stellar Age | 2.410 Gyr |
| Apparent Magnitude | V: 8.230 · G: 8.091 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 6.150000 AU |
| Orbital Period | 5062 days |
| Mean Orbital Velocity | 13.2 km/s |
| Orbital Eccentricity (e) | 0.12500 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.31 g/cm³ (126.6 km/s vesc) |
| Insolation Flux | 0.0565 S⊕ (~77 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 251.800 LY (77.197 pc) |