HD 8535 b
Astrophysical Synthesis & Habitability Characterization
HD 8535 b is a confirmed gas giant exoplanet orbiting the star HD 8535, located approximately 180.8 light-years (55.44 parsecs) from the Solar System. First announced in 2010 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14 Earth radii (1.25 Jupiter radii) and has a measured mass of 216.124 Earth masses (0.68 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.43 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 44 km/s.
In its orbital architecture around HD 8535, HD 8535 b completes one full revolution every 1313 Earth days (3.59Julian years) at a semi-major axis of 2.45 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 20.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.15 carries the world between 2.0825 AU at periapsis and 2.8175 AU at apoapsis, driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 14.000 R⊕, HD 8535 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 8535 is classified as a solar-type yellow star of spectral type G0 V with an effective photospheric temperature of 6,136 K, a radius of 1.19 R☉, a mass of 1.13 M☉, an estimated bolometric luminosity of 1.801 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.06 dex (metal-rich relative to the Sun). From Earth, HD 8535 shines at apparent V-band magnitude 7.7 (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 8535 |
| Spectral Type | G0 V |
| Effective Temp (Teff) | 6,136 K |
| Stellar Radius | 1.1900 R☉ |
| Stellar Mass | 1.1300 M☉ |
| Bolometric Luminosity | 1.801 L☉ |
| Metallicity [Fe/H] | 0.060 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 7.700 · G: 7.561 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.450000 AU |
| Orbital Period | 1313 days |
| Mean Orbital Velocity | 20.3 km/s |
| Orbital Eccentricity (e) | 0.15000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.43 g/cm³ (44 km/s vesc) |
| Insolation Flux | 0.3584 S⊕ (~488 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 180.800 LY (55.440 pc) |