HD 23079 b
Astrophysical Synthesis & Habitability Characterization
HD 23079 b is a confirmed gas giant exoplanet orbiting the star HD 23079, located approximately 109.1 light-years (33.46 parsecs) from the Solar System. First announced in 2001 by Anglo-Australian Telescope using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.2 Earth radii (1.18 Jupiter radii) and has a measured mass of 845.424 Earth masses (2.66 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.03 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 4.85 g⊕ (47.56 m/s²), and an escape velocity of 89.5 km/s.
In its orbital architecture around HD 23079, HD 23079 b completes one full revolution every 735.74 Earth days (2.01Julian years) at a semi-major axis of 1.6 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 23.7 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.07348 carries the world between 1.4824 AU at periapsis and 1.7176 AU at apoapsis, driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.200 R⊕, HD 23079 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 23079 is classified as a warm F-type star of spectral type F9.5 V with an effective photospheric temperature of 5,994 K, a radius of 1.08 R☉, a mass of 1.16 M☉, an estimated bolometric luminosity of 1.351 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.6 Gyr and a metallicity of [Fe/H] = -0.129 dex (metal-poor relative to the Sun). From Earth, HD 23079 shines at apparent V-band magnitude 7.12 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 23079 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 23079 b sharing its stellar neighborhood alongside HD 23079 c.
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: Anglo-Australian Telescope · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 23079 |
| Spectral Type | F9.5 V |
| Effective Temp (Teff) | 5,994 K |
| Stellar Radius | 1.0800 R☉ |
| Stellar Mass | 1.1600 M☉ |
| Bolometric Luminosity | 1.351 L☉ |
| Metallicity [Fe/H] | -0.129 dex |
| Stellar Age | 2.600 Gyr |
| Apparent Magnitude | V: 7.120 · G: 6.962 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.600000 AU |
| Orbital Period | 735.74 days |
| Mean Orbital Velocity | 23.7 km/s |
| Orbital Eccentricity (e) | 0.07348 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.03 g/cm³ (89.5 km/s vesc) |
| Insolation Flux | 0.5273 S⊕ (~718 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 109.100 LY (33.459 pc) |