HD 124330 b
Astrophysical Synthesis & Habitability Characterization
HD 124330 b is a confirmed gas giant exoplanet orbiting the star HD 124330, located approximately 196.3 light-years (60.2 parsecs) from the Solar System. First announced in 2021 by Haute-Provence 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 238.371 Earth masses (0.75 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.48 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 46.2 km/s.
In its orbital architecture around HD 124330, HD 124330 b completes one full revolution every 270.66 Earth days at a semi-major axis of 0.86 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 34.6 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.34, swinging from 0.5676 AU at periapsis out to 1.1524 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 14.000 R⊕, HD 124330 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 124330 is classified as a solar-type yellow star of spectral type G4 IV with an effective photospheric temperature of 5,873 K, a radius of 1.3045 R☉, a mass of 1.15 M☉, an estimated bolometric luminosity of 1.816 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.22 dex (metal-rich relative to the Sun). From Earth, HD 124330 shines at apparent V-band magnitude 7.88 (accessible to binoculars and small amateur telescopes) 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 124330 |
| Spectral Type | G4 IV |
| Effective Temp (Teff) | 5,873 K |
| Stellar Radius | 1.3045 R☉ |
| Stellar Mass | 1.1500 M☉ |
| Bolometric Luminosity | 1.816 L☉ |
| Metallicity [Fe/H] | 0.220 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 7.880 · G: 7.717 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.860000 AU |
| Orbital Period | 270.66 days |
| Mean Orbital Velocity | 34.6 km/s |
| Orbital Eccentricity (e) | 0.34000 |
| Orbital Inclination (i) | 0.8084° |
| Mean Bulk Density | 0.48 g/cm³ (46.2 km/s vesc) |
| Insolation Flux | 2.9422 S⊕ (~4,004 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 196.300 LY (60.198 pc) |