HD 86226 b
Astrophysical Synthesis & Habitability Characterization
HD 86226 b is a confirmed gas giant exoplanet orbiting the star HD 86226, located approximately 149 light-years (45.68 parsecs) from the Solar System. First announced in 2009 by Las Campanas Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14.3 Earth radii (1.28 Jupiter radii) and has a measured mass of 143.024 Earth masses (0.45 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.27 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.7 g⊕ (6.86 m/s²), and an escape velocity of 35.4 km/s.
In its orbital architecture around HD 86226, HD 86226 b completes one full revolution every 1628 Earth days (4.46Julian years) at a semi-major axis of 2.73 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 18.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.059 carries the world between 2.5689 AU at periapsis and 2.8911 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 176 K (-97°C / -143°F) and an incident flux of 0.16 S⊕ (~215 W/m²), surface water and volatile species on HD 86226 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 86226 is classified as a solar-type yellow star of spectral type G1 V with an effective photospheric temperature of 5,863 K, a radius of 1.053 R☉, a mass of 1.019 M☉, an estimated bolometric luminosity of 1.176 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.6 Gyr and a metallicity of [Fe/H] = 0.018 dex (near-solar heavy-element abundance). From Earth, HD 86226 shines at apparent V-band magnitude 7.93 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 86226 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 86226 b sharing its stellar neighborhood alongside HD 86226 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: Las Campanas Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 86226 |
| Spectral Type | G1 V |
| Effective Temp (Teff) | 5,863 K |
| Stellar Radius | 1.0530 R☉ |
| Stellar Mass | 1.0190 M☉ |
| Bolometric Luminosity | 1.176 L☉ |
| Metallicity [Fe/H] | 0.018 dex |
| Stellar Age | 4.600 Gyr |
| Apparent Magnitude | V: 7.930 · G: 7.771 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.730000 AU |
| Orbital Period | 1628 days |
| Mean Orbital Velocity | 18.2 km/s |
| Orbital Eccentricity (e) | 0.05900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.27 g/cm³ (35.4 km/s vesc) |
| Insolation Flux | 0.1583 S⊕ (~215 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 149.000 LY (45.683 pc) |