HD 23596 b
Astrophysical Synthesis & Habitability Characterization
HD 23596 b is a confirmed gas giant exoplanet orbiting the star HD 23596, located approximately 169.6 light-years (52 parsecs) from the Solar System. First announced in 2003 by Haute-Provence Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.4 Earth radii (1.11 Jupiter radii) and has a measured mass of 3786.608 Earth masses (11.91 Jupiter masses). Combining its mass and radius yields a mean bulk density of 10.95 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 24.63 g⊕ (241.54 m/s²), and an escape velocity of 195.5 km/s.
In its orbital architecture around HD 23596, HD 23596 b completes one full revolution every 1535.119 Earth days (4.2Julian years) at a semi-major axis of 2.694 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 19.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.282, swinging from 1.9343 AU at periapsis out to 3.4537 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.400 R⊕, HD 23596 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 23596 is classified as a warm F-type star of spectral type F8 with an effective photospheric temperature of 6,040 K, a radius of 1.53 R☉, a mass of 1.1 M☉, an estimated bolometric luminosity of 2.795 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.68 Gyr and a metallicity of [Fe/H] = 0.33 dex (metal-rich relative to the Sun). From Earth, HD 23596 shines at apparent V-band magnitude 7.261 (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 23596 |
| Spectral Type | F8 |
| Effective Temp (Teff) | 6,040 K |
| Stellar Radius | 1.5300 R☉ |
| Stellar Mass | 1.1000 M☉ |
| Bolometric Luminosity | 2.795 L☉ |
| Metallicity [Fe/H] | 0.330 dex |
| Stellar Age | 5.680 Gyr |
| Apparent Magnitude | V: 7.261 · G: 7.104 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.694000 AU |
| Orbital Period | 1535.119 days |
| Mean Orbital Velocity | 19.1 km/s |
| Orbital Eccentricity (e) | 0.28200 |
| Orbital Inclination (i) | 38.8980° |
| Mean Bulk Density | 10.95 g/cm³ (195.5 km/s vesc) |
| Insolation Flux | 0.3957 S⊕ (~539 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 169.600 LY (52.002 pc) |