HD 145675 c
Astrophysical Synthesis & Habitability Characterization
HD 145675 c is a confirmed gas giant exoplanet orbiting the star 14 Her, located approximately 58.5 light-years (17.93 parsecs) from the Solar System. First announced in 2021 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.6 Earth radii (1.12 Jupiter radii) and has a measured mass of 2510.844 Earth masses (7.9 Jupiter masses). Combining its mass and radius yields a mean bulk density of 6.92 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 15.82 g⊕ (155.14 m/s²), and an escape velocity of 157.9 km/s.
In its orbital architecture around 14 Her, HD 145675 c completes one full revolution every 15732.459 Earth days (43.07Julian years) at a semi-major axis of 20 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 13.8 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.52, swinging from 9.6 AU at periapsis out to 30.4 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 56 K (-217°C / -359°F) and an incident flux of 0.00 S⊕ (~2 W/m²), surface water and volatile species on HD 145675 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star 14 Her is classified as an orange K-type star of spectral type K0 with an effective photospheric temperature of 5,338 K, a radius of 0.93 R☉, a mass of 0.97 M☉, an estimated bolometric luminosity of 0.63 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.6 Gyr and a metallicity of [Fe/H] = 0.43 dex (metal-rich relative to the Sun). From Earth, 14 Her shines at apparent V-band magnitude 6.619 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The 14 Her system is a multi-planet architecture hosting 2 confirmed worlds, with HD 145675 c sharing its stellar neighborhood alongside 14 Her 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | 14 Her |
| Spectral Type | K0 |
| Effective Temp (Teff) | 5,338 K |
| Stellar Radius | 0.9300 R☉ |
| Stellar Mass | 0.9700 M☉ |
| Bolometric Luminosity | 0.63 L☉ |
| Metallicity [Fe/H] | 0.430 dex |
| Stellar Age | 4.600 Gyr |
| Apparent Magnitude | V: 6.619 · G: 6.383 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 20.000000 AU |
| Orbital Period | 15732.459 days |
| Mean Orbital Velocity | 13.8 km/s |
| Orbital Eccentricity (e) | 0.52000 |
| Orbital Inclination (i) | 116.3000° |
| Mean Bulk Density | 6.92 g/cm³ (157.9 km/s vesc) |
| Insolation Flux | 0.0018 S⊕ (~2 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 58.500 LY (17.932 pc) |