HD 8326 b
Astrophysical Synthesis & Habitability Characterization
HD 8326 b is a confirmed gas giant exoplanet orbiting the star HD 8326, located approximately 100.1 light-years (30.69 parsecs) from the Solar System. First announced in 2019 by Las Campanas Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 9.58 Earth radii (0.85 Jupiter radii) and has a measured mass of 66.6 Earth masses (0.21 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.42 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.73 g⊕ (7.16 m/s²), and an escape velocity of 29.5 km/s.
In its orbital architecture around HD 8326, HD 8326 b completes one full revolution every 158.991 Earth days at a semi-major axis of 0.533 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 36.5 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.2 carries the world between 0.4264 AU at periapsis and 0.6396 AU at apoapsis, driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 9.580 R⊕, HD 8326 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star HD 8326 is classified as an orange K-type star of spectral type K2 V with an effective photospheric temperature of 4,914 K, a radius of 0.7832 R☉, a mass of 0.8 M☉, an estimated bolometric luminosity of 0.321 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, HD 8326 shines at apparent V-band magnitude 8.76 (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: Las Campanas Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 8326 |
| Spectral Type | K2 V |
| Effective Temp (Teff) | 4,914 K |
| Stellar Radius | 0.7832 R☉ |
| Stellar Mass | 0.8000 M☉ |
| Bolometric Luminosity | 0.321 L☉ |
| Metallicity [Fe/H] | 0.040 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 8.760 · G: 8.475 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.533000 AU |
| Orbital Period | 158.991 days |
| Mean Orbital Velocity | 36.5 km/s |
| Orbital Eccentricity (e) | 0.20000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.42 g/cm³ (29.5 km/s vesc) |
| Insolation Flux | 1.1342 S⊕ (~1,544 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 100.100 LY (30.686 pc) |