HD 39091 b
Astrophysical Synthesis & Habitability Characterization
HD 39091 b is a confirmed gas giant exoplanet orbiting the star HD 39091, located approximately 59.6 light-years (18.27 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 12.3 Earth radii (1.1 Jupiter radii) and has a measured mass of 4481.381 Earth masses (14.1 Jupiter masses). Combining its mass and radius yields a mean bulk density of 13.28 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 29.62 g⊕ (290.47 m/s²), and an escape velocity of 213.5 km/s.
In its orbital architecture around HD 39091, HD 39091 b completes one full revolution every 2088.8 Earth days (5.72Julian years) at a semi-major axis of 3.28 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 17.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.642, swinging from 1.1742 AU at periapsis out to 5.3858 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 173 K (-100°C / -148°F) and an incident flux of 0.13 S⊕ (~183 W/m²), surface water and volatile species on HD 39091 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 39091 is classified as a solar-type yellow star of spectral type G0 V with an effective photospheric temperature of 5,998 K, a radius of 1.17 R☉, a mass of 1.07 M☉, an estimated bolometric luminosity of 1.59 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.92 Gyr and a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, HD 39091 shines at apparent V-band magnitude 5.65 (visible to the unaided human eye under dark skies) in the Southern celestial hemisphere. The HD 39091 system is a multi-planet architecture hosting 3 confirmed worlds, with HD 39091 b sharing its stellar neighborhood alongside pi Men c, pi Men d.
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 39091 |
| Spectral Type | G0 V |
| Effective Temp (Teff) | 5,998 K |
| Stellar Radius | 1.1700 R☉ |
| Stellar Mass | 1.0700 M☉ |
| Bolometric Luminosity | 1.59 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | 3.920 Gyr |
| Apparent Magnitude | V: 5.650 · G: 5.513 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 3.280000 AU |
| Orbital Period | 2088.8 days |
| Mean Orbital Velocity | 17.1 km/s |
| Orbital Eccentricity (e) | 0.64200 |
| Orbital Inclination (i) | 45.8000° |
| Mean Bulk Density | 13.28 g/cm³ (213.5 km/s vesc) |
| Insolation Flux | 0.1342 S⊕ (~183 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 59.600 LY (18.270 pc) |