HD 162020 b
Astrophysical Synthesis & Habitability Characterization
HD 162020 b is a confirmed gas giant exoplanet orbiting the star HD 162020, located approximately 100.5 light-years (30.83 parsecs) from the Solar System. First announced in 2002 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.5 Earth radii (1.12 Jupiter radii) and has a measured mass of 3127.447 Earth masses (9.84 Jupiter masses). Combining its mass and radius yields a mean bulk density of 8.83 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 20.02 g⊕ (196.33 m/s²), and an escape velocity of 176.9 km/s.
In its orbital architecture around HD 162020, HD 162020 b completes one full revolution every 8.428 Earth days at a semi-major axis of 0.08 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 103.3 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.28, swinging from 0.0576 AU at periapsis out to 0.1024 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 650 K (+377°C / +711°F) and receiving 39.06 S⊕ (~53,164 W/m²), HD 162020 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 162020 is classified as an orange K-type star of spectral type K3 V with an effective photospheric temperature of 4,723 K, a radius of 0.75 R☉, a mass of 0.42 M☉, an estimated bolometric luminosity of 0.251 L☉. Stellar evolution modeling indicates an estimated stellar age of 6 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, HD 162020 shines at apparent V-band magnitude 9.1 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere.
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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 162020 |
| Spectral Type | K3 V |
| Effective Temp (Teff) | 4,723 K |
| Stellar Radius | 0.7500 R☉ |
| Stellar Mass | 0.4200 M☉ |
| Bolometric Luminosity | 0.251 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | 6.000 Gyr |
| Apparent Magnitude | V: 9.100 · G: 8.759 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.080000 AU |
| Orbital Period | 8.428 days |
| Mean Orbital Velocity | 103.3 km/s |
| Orbital Eccentricity (e) | 0.28000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 8.83 g/cm³ (176.9 km/s vesc) |
| Insolation Flux | 39.0625 S⊕ (~53,164 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 100.500 LY (30.825 pc) |