HD 86081 b
Astrophysical Synthesis & Habitability Characterization
HD 86081 b is a confirmed gas giant exoplanet orbiting the star HD 86081, located approximately 339 light-years (103.94 parsecs) from the Solar System. First announced in 2006 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.6 Earth radii (1.21 Jupiter radii) and has a measured mass of 470.388 Earth masses (1.48 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.03 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.54 g⊕ (24.91 m/s²), and an escape velocity of 65.8 km/s.
In its orbital architecture around HD 86081, HD 86081 b completes one full revolution every 2.138 Earth days at a semi-major axis of 0.0346 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 176.1 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.0119 (ranging from 0.0342 AU at periapsis to 0.035 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1860 K (+1587°C / +2889°F) and receiving 2,003.77 S⊕ (~2,727,131 W/m²), HD 86081 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 86081 is classified as a warm F-type star of spectral type F8 with an effective photospheric temperature of 5,939 K, a radius of 1.46 R☉, a mass of 1.21 M☉, an estimated bolometric luminosity of 2.379 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.61 Gyr and a metallicity of [Fe/H] = 0.22 dex (metal-rich relative to the Sun). From Earth, HD 86081 shines at apparent V-band magnitude 8.73 (accessible to binoculars and small amateur telescopes) in the Southern 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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 86081 |
| Spectral Type | F8 |
| Effective Temp (Teff) | 5,939 K |
| Stellar Radius | 1.4600 R☉ |
| Stellar Mass | 1.2100 M☉ |
| Bolometric Luminosity | 2.379 L☉ |
| Metallicity [Fe/H] | 0.220 dex |
| Stellar Age | 3.610 Gyr |
| Apparent Magnitude | V: 8.730 · G: 8.588 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.034600 AU |
| Orbital Period | 2.138 days |
| Mean Orbital Velocity | 176.1 km/s |
| Orbital Eccentricity (e) | 0.01190 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.03 g/cm³ (65.8 km/s vesc) |
| Insolation Flux | 2003.7697 S⊕ (~2,727,131 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 339.000 LY (103.936 pc) |