HD 33564 b
Astrophysical Synthesis & Habitability Characterization
HD 33564 b is a confirmed gas giant exoplanet orbiting the star HD 33564, located approximately 68.3 light-years (20.95 parsecs) from the Solar System. First announced in 2005 by Haute-Provence 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 2892.1 Earth masses (9.1 Jupiter masses). Combining its mass and radius yields a mean bulk density of 8.16 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 18.51 g⊕ (181.52 m/s²), and an escape velocity of 170.1 km/s.
In its orbital architecture around HD 33564, HD 33564 b completes one full revolution every 388 Earth days (1.06Julian years) at a semi-major axis of 1.1 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 30.8 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.34, swinging from 0.726 AU at periapsis out to 1.474 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.500 R⊕, HD 33564 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 33564 is classified as a warm F-type star of spectral type F6 V with an effective photospheric temperature of 6,250 K, a radius of 1.4367 R☉, a mass of 1.25 M☉, an estimated bolometric luminosity of 2.826 L☉. Stellar evolution modeling indicates an estimated stellar age of 3 Gyr and a metallicity of [Fe/H] = -0.12 dex (metal-poor relative to the Sun). From Earth, HD 33564 shines at apparent V-band magnitude 5.101 (visible to the unaided human eye under dark skies) in the Northern 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: Haute-Provence Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 33564 |
| Spectral Type | F6 V |
| Effective Temp (Teff) | 6,250 K |
| Stellar Radius | 1.4367 R☉ |
| Stellar Mass | 1.2500 M☉ |
| Bolometric Luminosity | 2.826 L☉ |
| Metallicity [Fe/H] | -0.120 dex |
| Stellar Age | 3.000 Gyr |
| Apparent Magnitude | V: 5.101 · G: 4.972 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.100000 AU |
| Orbital Period | 388 days |
| Mean Orbital Velocity | 30.8 km/s |
| Orbital Eccentricity (e) | 0.34000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 8.16 g/cm³ (170.1 km/s vesc) |
| Insolation Flux | 2.8331 S⊕ (~3,856 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 68.300 LY (20.953 pc) |